Investments, Debt and Equity Securities [Abstract] Short-Term Investments Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Fair Value Disclosures [Abstract] Fair Value Measurements Fair Value Disclosures [Text Block] Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Accounting Policies [Abstract] Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Summary of significant accounting policies. Product and Service Product and Service [Axis] Product and Service Product and Service [Domain] Complementary products Complementary Products [Member] Complementary products. Tandem Pump Tandem Pump [Member] Tandem pump. Slim cartridges and infusion sets Slim Cartridges And Infusion Sets [Member] Slim cartridges and infusion sets. SEC Schedule, 12-09, Valuation Allowances and Reserves Type SEC Schedule, 12-09, Valuation Allowances and Reserves Type [Axis] SEC Schedule, 12-09, Valuation Allowances and Reserves SEC Schedule, 12-09, Valuation Allowances and Reserves [Domain] Warranty reserves SEC Schedule, 12-09, Reserve, Warranty [Member] Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Summary of significant accounting policies. Number of operating segments Number of Operating Segments Offered period for sales return Offered Period For Sales Return Prior To Expiration Offered period for sales return prior to expiration. Allowance for product returns Allowance For Sales Returns Allowance for sales returns. Warranty period offered Products Warranty Period Products warranty period. Warranty reserve Standard and Extended Product Warranty Accrual Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock Common Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Accumulated Deficit Retained Earnings [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance (shares) Shares, Outstanding Beginning balance Stockholders' Equity Attributable to Parent Exercise of stock options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Exercise of stock options Stock Issued During Period, Value, Stock Options Exercised Exercise of common stock warrants (shares) Stock Issued During Period Shares Common Stock Warrants Exercised Stock issued during period shares common stock warrants exercised. Exercise of common stock warrants Stock Issued During Period Value Common Stock Warrants Exercised Stock issued during period value common stock warrants exercised. Fair value of common stock warrants at time of exercise Fair Value Of Common Stock Warrants At Time Of Exercise Fair value of common stock warrants at time of exercise. Stock-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Unrealized gain on short-term investments Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax Foreign currency translation gain (loss) Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Net loss Net Income (Loss) Attributable to Parent Ending balance (shares) Ending balance Equity [Abstract] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Statement of Financial Position [Abstract] Common stock, par value (in usd per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Balance at beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Loss recognized from the change in fair value of common stock warrants Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease) Decrease in fair value from warrants exercised during the period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances Balance at end of period Leases [Abstract] Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Lease Arrangements [Axis] Lease Arrangements [Axis] Lease Arrangements [Axis] Lease Arrangements [Domain] Lease Arrangements [Domain] [Domain] for Lease Arrangements [Axis] Vista Sorrento Original Lease Vista Sorrento Lease [Member] Vista Sorrento Lease [Member] Adjustments for New Accounting Pronouncements Adjustments for New Accounting Pronouncements [Axis] Type of Adoption Type of Adoption [Domain] Accounting Standards Update 2016-02 Accounting Standards Update 2016-02 [Member] Initial Application Period Cumulative Effect Transition Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition Initial Application Period Cumulative Effect Transition [Domain] Difference Between Leases Guidance in Effect Before and After Topic 842 Difference Between Leases Guidance In Effect Before And After Topic842 [Member] Difference between leases guidance in effect before and after Topic 842. Balance Sheet Location Balance Sheet Location [Axis] Balance Sheet Location Balance Sheet Location [Domain] Other Current Liabilities Other Current Liabilities [Member] Geographical Geographical [Axis] Geographical Geographical [Domain] 10935 Vista Sorrento Parkway, San Diego, California Vista Sorrento Parkway Lease [Member] Vista Sorrento Parkway Lease [Member] Shoreline Drive, Boise, Idaho Shoreline Drive, Boise, Idaho [Member] Shoreline Drive, Boise, Idaho [Member] High Bluff Drive, San Diego, California High Bluff Drive, San Diego, California [Member] High Bluff Drive, San Diego, California [Member] Range Range [Axis] Range Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Operating lease, liability Operating Lease, Liability Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Deferred rent, current Deferred Rent Credit, Current Deferred rent—long-term Deferred Rent Credit, Noncurrent Area of office space leased Area of Real Estate Property Term of contract Lessee, Operating Lease, Term of Contract Operating lease extension period Lessee, Operating Lease, Renewal Term Future minimum lease payments Lessee, Operating Lease, Liability, Payments, Due Lease cost Lease, Cost Operating lease, cost Operating Lease, Cost Short-term lease, cost Short-term Lease, Cost Operating lease, payments Operating Lease, Payments Operating lease, weighted average remaining lease term Operating Lease, Weighted Average Remaining Lease Term Operating lease, weighted average discount rate, percent Operating Lease, Weighted Average Discount Rate, Percent Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Accounts Receivable And Inventories Disclosure [Abstract] Accounts Receivable And Inventories Disclosure [Abstract] Allowance for Doubtful Accounts Receivable [Roll Forward] Allowance for Doubtful Accounts Receivable [Roll Forward] Balance at beginning of the period Allowance for Doubtful Accounts Receivable Provision for expected credit losses Provision for Doubtful Accounts Write-offs and adjustments, net of recoveries Allowance for Doubtful Accounts Receivable, Write-offs Balance at end of the period Statement of Cash Flows [Abstract] Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net loss Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Adjustments to reconcile net loss to net cash used in operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization expense Depreciation, Depletion and Amortization Provision for expected credit losses Provision (benefit) for inventory obsolescence Inventory Write-down Change in fair value of common stock warrants Fair Value Adjustment of Warrants Amortization of discount on short-term investments Investment Income, Net, Amortization of Discount and Premium Stock-based compensation expense Share-based Compensation Other Other Operating Activities, Cash Flow Statement Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable, net Increase (Decrease) in Accounts Receivable Inventories, net Increase (Decrease) in Inventories Prepaid and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Other long-term assets Increase (Decrease) in Other Noncurrent Assets Accounts payable Increase (Decrease) in Accounts Payable Accrued expenses Increase (Decrease) in Accrued Liabilities Employee-related liabilities Increase (Decrease) in Employee Related Liabilities Deferred revenue Increase (Decrease) in Contract with Customer, Liability Other current liabilities Increase (Decrease) in Other Current Liabilities Other long-term liabilities Increase (Decrease) in Other Noncurrent Liabilities Net cash used in operating activities Net Cash Provided by (Used in) Operating Activities Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Purchases of short-term investments Payments to Acquire Short-term Investments Proceeds from maturities of short-term investments Proceeds from Maturities, Prepayments and Calls of Short-term Investments Proceeds from sales of short-term investments Proceeds from Sale of Short-term Investments Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Net cash provided by investing activities Net Cash Provided by (Used in) Investing Activities Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from exercise of common stock warrants Proceeds from Warrant Exercises Proceeds from issuance of common stock under Company stock plans Proceeds from Issuance of Common Stock Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Effect of foreign exchange rate changes on cash Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Net increase (decrease) in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash and cash equivalents at beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations Cash and cash equivalents at end of period Supplemental disclosures of cash flow information Supplemental Cash Flow Information [Abstract] Income taxes paid Income Taxes Paid Supplemental schedule of non-cash investing and financing activities Noncash Investing and Financing Items [Abstract] Right-of-use assets obtained in exchange for operating lease obligations Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Property and equipment included in accounts payable Capital Expenditures Incurred but Not yet Paid Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization And Basis Of Presentation [Table] Organization And Basis Of Presentation [Table] Organization and basis of presentation. Insulin Pump Insulin Pump [Member] Insulin pump. Organization And Basis Of Presentation [Line Items] Organization And Basis Of Presentation [Line Items] Organization and basis of presentation. Expected life span term Product Life Span Term Product life span term. Cash and cash equivalents and short-term investments Cash, Cash Equivalents, and Short-term Investments Accumulated deficit Retained Earnings (Accumulated Deficit) Assets Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Short-term investments Short-term Investments Accounts receivable, net Accounts Receivable, Net, Current Inventories Inventory, Net Prepaid and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Property and equipment, net Property, Plant and Equipment, Net Other long-term assets Other Assets, Noncurrent Total assets Assets Liabilities and Stockholders’ Equity Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued expenses Accrued Liabilities, Current Employee-related liabilities Employee-related Liabilities, Current Deferred revenue Contract with Customer, Liability, Current Common stock warrants Common Stock Warrants Common stock warrants. Operating lease liabilities Operating Lease, Liability, Current Other current liabilities Other Liabilities, Current Total current liabilities Liabilities, Current Operating lease liabilities - long-term Operating Lease, Liability, Noncurrent Other long-term liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Commitments and contingencies (Note 9) Commitments and Contingencies Stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Common stock, $0.001 par value; 200,000 shares authorized, 60,071 and 59,396 shares issued and outstanding at March 31, 2020 (unaudited) and December 31, 2019, respectively. Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders’ equity Total liabilities and stockholders’ equity Liabilities and Equity Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Employee Stock Option [Member] Sale of Stock [Axis] Sale of Stock Sale of Stock [Domain] Stock Options Employee Stock Option [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Weighted average grant date fair value (in usd per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected term (in years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Antidilutive Securities Antidilutive Securities [Axis] Antidilutive Securities, Name Antidilutive Securities, Name [Domain] Shares underlying outstanding warrants Warrant [Member] Shares underlying outstanding stock options Stock Options Issued And Outstanding [Member] Stock options issued and outstanding. Shares authorized for future equity award grants Grant [Member] Shares authorized for issuance pursuant to awards granted under the ESPP Stock Compensation Plan [Member] Common stock reserved for future issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Schedule of Accounts Receivable Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Accounts Receivable, Allowance for Credit Loss Accounts Receivable, Allowance for Credit Loss [Table Text Block] Accounts Receivable, Allowance for Credit Loss [Table Text Block] Summary of Inventories Schedule of Inventory, Current [Table Text Block] Income Statement [Abstract] Sales Revenue from Contract with Customer, Excluding Assessed Tax Cost of sales Cost of Goods and Services Sold Gross profit Gross Profit Operating expenses: Operating Expenses [Abstract] Selling, general and administrative Selling, General and Administrative Expense Research and development Research and Development Expense Total operating expenses Operating Expenses Operating loss Operating Income (Loss) Other income (expense), net: Other Nonoperating Income (Expense) [Abstract] Interest and other income Interest and Other Income Interest and other expense Interest Expense, Other Change in fair value of common stock warrants Total other expense, net Other Nonoperating Income (Expense) Loss before income taxes Income (Loss) Attributable to Parent, before Tax Income tax expense Income Tax Expense (Benefit) Net loss Other comprehensive loss: Other Comprehensive Income (Loss), Net of Tax [Abstract] Comprehensive loss Comprehensive Income (Loss), Net of Tax, Attributable to Parent Net loss per share, basic and diluted (in dollars per share) Earnings Per Share, Basic and Diluted Weighted average shares used to compute basic and diluted net loss per share (in shares) Weighted Average Number of Shares Outstanding, Basic and Diluted Raw materials Inventory, Raw Materials, Gross Work-in-process Inventory, Work in Process, Gross Finished goods Inventory, Finished Goods, Gross Inventories Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of Assumptions Used to Estimate Fair Values of Common Stock Warrants Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Summary of Changes in Fair Value of Total Level 3 Financial Assets Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Schedule of Future Minimum Payments Under Non-cancellable Operating Leases Lessee, Operating Lease, Liability, Maturity [Table Text Block] Number of legal proceedings, regulatory matters, or other, disputes or claims Number Of Legal Proceedings Regulatory Matters Or Other Disputes Or Claims Number of legal proceedings, regulatory matters, or other, disputes or claims. Cash Cash Equivalents And Short Term Investments [Table] Cash Cash Equivalents And Short Term Investments [Table] Cash cash equivalents and short term investments. Investment Type Investment Type [Axis] Investments Investments [Domain] Commercial paper Commercial Paper [Member] U.S. Government-sponsored enterprise US Government-sponsored Enterprises Debt Securities [Member] U.S. Treasury securities US Treasury Securities [Member] Corporate debt securities Corporate Debt Securities [Member] Cash Cash Equivalents And Short Term Investments [Line Items] Cash Cash Equivalents And Short Term Investments [Line Items] Cash cash equivalents and short term investments. Available-for-sale securities, Maturity (in years) Short Term Investments, Maturity Short term investments maturity. Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Gross Unrealized Gain Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Loss Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Estimated Fair Value Debt Securities, Available-for-sale Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Reclassification Reclassification, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Segment Reporting Segment Reporting, Policy [Policy Text Block] Accounts Receivable Receivables, Policy [Policy Text Block] Fair Value of Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Operating Lease Right-of-Use Assets and Liabilities Lessee, Leases [Policy Text Block] Revenue Recognition Revenue Recognition, Policy [Policy Text Block] Warranty Reserve Standard Product Warranty, Policy [Policy Text Block] Stock-Based Compensation Compensation Related Costs, Policy [Policy Text Block] Net Loss Per Share Earnings Per Share, Policy [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] 2020 (remaining) Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year 2021 Lessee, Operating Lease, Liability, Payments, Due Year Two 2022 Lessee, Operating Lease, Liability, Payments, Due Year Three 2023 Lessee, Operating Lease, Liability, Payments, Due Year Four 2024 Lessee, Operating Lease, Liability, Payments, Due Year Five Thereafter Lessee, Operating Lease, Liability, Payments, Due after Year Five Total undiscounted lease payments Less: amount representing interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Present value of operating lease liabilities Less: current portion of operating lease liabilities Leases Lessee, Operating Leases [Text Block] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Axis] Timing of Transfer of Good or Service [Domain] Timing of Transfer of Good or Service [Domain] Transferred over Time Transferred over Time [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Deferred revenue Other long-term liabilities Contract with Customer, Liability, Noncurrent Total Contract with Customer, Liability Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Cost of sales Cost of Sales [Member] Selling, general & administrative Selling, General and Administrative Expenses [Member] Research and development Research and Development Expense [Member] Compensation cost Allocated Share-based Compensation Expense Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Class of Warrant or Right Class of Warrant or Right [Axis] Class of Warrant or Right Class of Warrant or Right [Domain] Series A warrants Series A Warrants [Member] Series A warrants. Sale of Stock Secondary Public Offering Secondary Public Offering [Member] Secondary public offering. Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Public offering period Public Offering Period Public offering period. Warrants issue to purchase common stock (in shares) Class of Warrant or Right, Number of Securities Called by Warrants or Rights Warrants exercise price (USD per share) Class of Warrant or Right, Exercise Price of Warrants or Rights Warrants initial value Fair Value Of Warrant Liability Fair value of warrant liability. Loss recognized from change in fair value of common stock warrants Outstanding warrants (in shares) Class of Warrant or Right, Outstanding Accounts Receivable and Inventories Accounts Receivable And Inventory Disclosure [Text Block] Current Assets Disclosure [Text Block] Fair Value Measurement Inputs and Valuation Techniques [Table] Fair Value Measurement Inputs and Valuation Techniques [Table] Measurement Input Type Measurement Input Type [Axis] Measurement Input Type Measurement Input Type [Domain] Risk-free interest rate Measurement Input, Risk Free Interest Rate [Member] Expected dividend yield Measurement Input, Expected Dividend Rate [Member] Expected volatility Measurement Input, Price Volatility [Member] Expected Term Measurement Input, Expected Term [Member] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Fair Value Measurement Inputs and Valuation Techniques [Line Items] Assumptions used to estimate fair value of common stock warrants Warrants and Rights Outstanding, Measurement Input Expected term (in years) Warrants and Rights Outstanding, Term Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward] Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward] Beginning balance Provision for warranties issued during the period Standard and Extended Product Warranty Accrual, Increase for Warranties Issued Settlements made during the period Standard and Extended Product Warranty Accrual, Decrease for Payments Decreases in warranty estimates Standard and Extended Product Warranty Accrual, Increase (Decrease) for Preexisting Warranties Ending balance Other current liabilities Product Warranty Accrual, Current Other long-term liabilities Product Warranty Accrual, Noncurrent Total warranty reserves Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Common stock warrants Options to purchase common stock ESPP Employee Stock [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive securities excluded from computation of earnings per share, amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Cover [Abstract] Document Type Document Type Document Quarterly Report Document Quarterly Report Document Period End Date Document Period End Date Document Transition Report Document Transition Report Entity File Number Entity File Number Entity Registrant Name Entity Registrant Name Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address, Address Line One Entity Address, Postal Zip Code Entity Address, Postal Zip Code Entity Address, City or Town Entity Address, City or Town Entity Address, State or Province Entity Address, State or Province City Area Code City Area Code Local Phone Number Local Phone Number Title of 12(b) Security Title of 12(b) Security Trading Symbol Trading Symbol Security Exchange Name Security Exchange Name Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Summary of Estimated Fair Value of Short-Term Investments Cash, Cash Equivalents and Investments [Table Text Block] Contract with Customer, Asset and Liability Contract with Customer, Asset and Liability [Table Text Block] Summary of Reconciliation of Change in Product Warranty Liabilities Schedule of Product Warranty Liability [Table Text Block] Schedule of Anti-Dilutive Securities Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Cash equivalents Cash Equivalents [Member] U.S. Government-sponsored enterprise US Government Agencies Debt Securities [Member] Measurement Frequency Measurement Frequency [Axis] Fair Value, Measurement Frequency Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Measurements, Recurring [Member] Level 2 [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV Fair Value Hierarchy and NAV [Domain] (Level 1) Fair Value, Inputs, Level 1 [Member] (Level 2) Fair Value, Inputs, Level 2 [Member] (Level 3) Fair Value, Inputs, Level 3 [Member] Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Axis] Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation Equity-Based Arrangements, Individual Contracts, Type of Deferred Compensation [Domain] Total assets Assets, Fair Value Disclosure Total liabilities Financial and Nonfinancial Liabilities, Fair Value Disclosure Accounts receivable Accounts Receivable, Gross Less allowance for credit losses Accounts receivable, net Accounts Receivable, Net Cash equivalents maturity term Cash Equivalents Maturity Term Cash equivalents maturity term. Common Stock Warrant Expiring March 2027 Common Stock Warrant Expiring March 2027 [Member] Common Stock Warrant Expiring March 2027 [Member] Common Stock Warrant Expiring Between August 2021 and August 2022 Common Stock Warrant Expiring Between August 2021 and August 2022 [Member] Common Stock Warrant Expiring Between August 2021 and August 2022 [Member] Vesting Vesting [Axis] Vesting Vesting [Domain] First anniversary Share-based Compensation Award, Tranche One [Member] Monthly vesting over following 3 years Share-based Compensation Award, Tranche Two [Member] Award Type Award Type [Axis] Equity Award Equity Award [Domain] Contingent stock options Contingent Employee Stock Options [Member] Contingent Employee Stock Options [Member] Plan Name Plan Name [Axis] Plan Name Plan Name [Domain] 2013 Plan Two Thousand Thirteen Plan [Member] 2013 plan. Common stock shares issued (in shares) Offering period Offering Period Offering period. Purchase period Purchase Period Purchase period. Purchase of common stock under ESPP (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Shares Purchased for Award Shares granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Award vesting percentage Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Total stock-based compensation expense capitalized as part of cost of inventory Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Capitalized Amount Schedule of Shares of Common Stock Reserved for Future Issuance Schedule Of Common Stock Reserved For Future Issuance Table [Text Block] Schedule of common stock reserved for future issuance. Schedule of Assumptions Used in Black-Scholes Option-Pricing Model Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Summary for Allocation of Stock-Based Compensation Expense Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Organization and Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]