Inogen (INGN) 10-Q 3 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 31, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Trading Symbol	INGN
Entity Registrant Name	Inogen Inc
Entity Central Index Key	1,294,133
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		20,260,695

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 86,009	$ 66,106
Marketable securities	22,331	16,793
Accounts receivable, net	29,717	19,872
Inventories, net	16,499	8,648
Deferred cost of revenue	439	397
Income tax receivable	1,612	2,158
Prepaid expenses and other current assets	1,470	870
Total current assets	158,077	114,844
Property and equipment
Rental equipment, net	54,684	54,677
Manufacturing equipment and tooling	5,850	4,680
Computer equipment and software	4,663	4,503
Furniture and equipment	757	732
Leasehold improvements	811	978
Land and building	125	125
Construction in process	430	578
Total property and equipment	67,320	66,273
Less accumulated depreciation	(40,485)	(35,593)
Property and equipment, net	26,835	30,680
Intangible assets, net	268	229
Deferred tax asset - noncurrent	9,514	15,464
Other assets	97	97
Total assets	194,791	161,314
Current liabilities
Accounts payable and accrued expenses	20,710	12,867
Accrued payroll	5,844	5,271
Current portion of long-term debt	80	315
Warranty reserve - current	1,559	1,226
Deferred revenue - current	2,035	2,323
Income tax payable		11
Total current liabilities	30,228	22,013
Long-term liabilities
Warranty reserve - noncurrent	1,838	747
Deferred revenue - noncurrent	6,343	4,199
Other noncurrent liabilities	300	337
Total liabilities	38,709	27,296
Commitments and contingencies (Note 9)
Stockholders' equity
Common stock, $0.001 par value per share; 200,000,000 authorized; 20,244,243 and 19,782,403 shares issued and outstanding as of September 30, 2016 and December 31, 2015, respectively	20	20
Additional paid-in capital	190,202	179,143
Accumulated deficit	(34,146)	(45,108)
Accumulated other comprehensive income (loss)	6	(37)
Total stockholders' equity	156,082	134,018
Total liabilities and stockholders' equity	$ 194,791	$ 161,314

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	20,244,243	19,782,403
Common stock, shares outstanding	20,244,243	19,782,403

Statements of Comprehensive Inc

Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue
Sales revenue	$ 47,177	$ 29,248	$ 125,566	$ 84,682
Rental revenue	7,245	11,530	26,412	33,877
Total revenue	54,422	40,778	151,978	118,559
Cost of revenue
Cost of sales revenue	24,271	16,046	63,824	46,501
Cost of rental revenue, including depreciation of $2,878 and $3,029 for the three months ended and $8,733 and $8,929 for the nine months ended, respectively	5,023	5,357	15,532	15,838
Total cost of revenue	29,294	21,403	79,356	62,339
Gross profit
Gross profit-sales revenue	22,906	13,202	61,742	38,181
Gross profit-rental revenue	2,222	6,173	10,880	18,039
Total gross profit	25,128	19,375	72,622	56,220
Operating expense
Research and development	1,350	1,116	3,897	2,954
Sales and marketing	9,679	8,132	28,220	22,623
General and administrative	8,702	6,413	23,812	19,066
Total operating expense	19,731	15,661	55,929	44,643
Income from operations	5,397	3,714	16,693	11,577
Other income (expense)
Interest expense	(1)	(5)	(6)	(18)
Interest income	61	28	126	66
Other income (expense)	(8)	(59)	78	(215)
Total other income (expense), net	52	(36)	198	(167)
Income before provision for income taxes	5,449	3,678	16,891	11,410
Provision for income taxes	1,994	982	5,929	3,683
Net income	3,455	2,696	10,962	7,727
Other comprehensive income, net of tax
Unrealized gain (loss) on foreign currency hedging during the period	10		(24)
Add: reclassification adjustment for losses included in net income	2		51
Total unrealized gain on foreign currency hedging	12		27
Unrealized gain (loss) on available-for-sale investments during the period	(4)		16
Total other comprehensive income, net of tax	8		43
Comprehensive income	$ 3,463	$ 2,696	$ 11,005	$ 7,727
Basic net income per share attributable to common stockholders (Note 5)	$ 0.17	$ 0.14	$ 0.55	$ 0.40
Diluted net income per share attributable to common stockholders (Note 5)	$ 0.16	$ 0.13	$ 0.52	$ 0.37
Weighted-average number of shares used in calculating net income per share attributable to common stockholders:
Basic common shares	20,157,688	19,428,653	19,986,544	19,303,057
Diluted common shares	21,100,725	20,783,550	20,924,022	20,690,499

Statements of Comprehensive In5

Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Depreciation	$ 2,878	$ 3,029	$ 8,733	$ 8,929

Statement of Stockholders' Equi

Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated deficit	Accumulated other comprehensive income (loss)
Beginning Balance at Dec. 31, 2014	$ 118,150	$ 19	$ 174,824	$ (56,693)
Beginning Balance, shares at Dec. 31, 2014		19,059,364
Stock-based compensation	2,343		2,343
Employee stock purchases	701		701
Employee stock purchases, shares		31,106
Stock options exercised	1,001		1,001
Stock options exercised, shares		496,203
Net income	7,727			7,727
Ending Balance at Sep. 30, 2015	129,922	$ 19	178,869	(48,966)
Ending Balance, shares at Sep. 30, 2015		19,586,673
Beginning Balance at Dec. 31, 2015	134,018	$ 20	179,143	(45,108)	$ (37)
Beginning Balance, shares at Dec. 31, 2015		19,782,403
Stock-based compensation	5,404		5,404
Employee stock purchases	1,055		1,055
Employee stock purchases, shares		37,378
Stock options exercised	$ 4,600		4,600
Stock options exercised, shares	424,462	424,462
Net income	$ 10,962			10,962
Other comprehensive income	43				43
Ending Balance at Sep. 30, 2016	$ 156,082	$ 20	$ 190,202	$ (34,146)	$ 6
Ending Balance, shares at Sep. 30, 2016		20,244,243

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities
Net income	$ 10,962	$ 7,727
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,290	10,468
Loss on rental units and other fixed assets	891	889
Gain on sale of former assets	(224)
Provision for sales returns and doubtful accounts	8,177	5,346
Provision for rental revenue adjustments	7,783	6,364
Provision for inventory obsolescence and other inventory losses, net of recoveries	141	131
Stock-based compensation expense	5,404	2,343
Deferred tax assets	5,950	3,682
Changes in operating assets and liabilities:
Accounts receivable	(25,812)	(13,251)
Inventories	(9,220)	(3,167)
Deferred cost of revenue	(42)	41
Income tax receivable	546	(32)
Prepaid expenses and other current assets	(600)	(774)
Accounts payable and accrued expenses	7,801	3,030
Accrued payroll	573	573
Warranty reserve	1,424	673
Deferred revenue	1,856	1,615
Income tax payable	(11)
Other noncurrent liabilities	(37)	(54)
Net cash provided by operating activities	25,852	25,604
Cash flows from investing activities
Purchases of available-for-sale investments	(26,321)	(33,557)
Maturities of available-for-sale investments	20,799	14,529
Investment in intangible assets	(112)	(21)
Investment in property and equipment	(6,071)	(9,780)
Proceeds from sale of former assets	328
Net cash used in investing activities	(11,377)	(28,829)
Cash flows from financing activities
Proceeds from stock options exercised	4,600	1,001
Proceeds from employee stock purchases	1,055	701
Repayment of debt from investment in intangible assets	(235)	(223)
Net cash provided by financing activities	5,420	1,479
Effect of exchange rates on cash	8
Net increase (decrease) in cash and cash equivalents	19,903	(1,746)
Cash and cash equivalents, beginning of period	66,106	56,836
Cash and cash equivalents, end of period	86,009	55,090
Supplemental disclosures of cash flow information
Cash paid during the period for interest	9	21
Cash paid (received) during the period for income taxes, net	$ (533)	$ 32

Business Overview

Business Overview	9 Months Ended
	Sep. 30, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business Overview	1. Business overview Inogen, Inc. (Company or Inogen) was incorporated in Delaware on November 27, 2001. The Company is a medical technology company that primarily develops, manufactures and markets innovative portable oxygen concentrators used to deliver supplemental long-term oxygen therapy to patients suffering from chronic respiratory conditions. Traditionally, these patients have relied on stationary oxygen concentrator systems for use in the home and oxygen tanks or cylinders for mobile use, which the Company calls the delivery model. The tanks and cylinders must be delivered regularly and have a finite amount of oxygen, which requires patients to plan activities outside of their homes around delivery schedules and a finite oxygen supply. Additionally, patients must attach long, cumbersome tubing to their stationary concentrators simply to enable mobility within their homes. The Company’s proprietary Inogen One ® ® ® ® Portable oxygen concentrators represented the fastest-growing segment of the Medicare oxygen therapy market between 2012 and 2015. The Company estimates based on 2015 Medicare data that patients using portable oxygen concentrators represent approximately 8% of the total addressable oxygen market in the United States, although the Medicare data does not account for cash-pay sales into the market. Based on 2015 industry data, the Company believes it was the leading worldwide manufacturer of portable oxygen concentrators, as well as the largest provider of portable oxygen concentrators to Medicare patients, as measured by dollar volume. The Company believes it is the only manufacturer of portable oxygen concentrators that employs a direct-to-consumer strategy in the United States, meaning the Company markets its products to patients, processes their physician paperwork, provides clinical support as needed and bills Medicare or insurance on their behalf. To pursue a direct-to-consumer strategy, the Company’s manufacturing competitors would need to meet national accreditation and state-by-state licensing requirements and secure Medicare billing privileges, as well as compete with the home medical equipment providers that many rely on across their entire homecare business. Since adopting the Company’s direct-to-consumer strategy in 2009 following its acquisition of Comfort Life Medical Supply, LLC, which had an active Medicare billing number but few other assets and limited business activities, the Company has directly sold or rented its Inogen oxygen concentrators to more than 196,000 patients as of September 30, 2016.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	2. Basis of presentation and summary of significant accounting policies The accompanying financial statements are unaudited. The balance sheet at December 31, 2015 has been derived from the audited financial statements of the Company. The accompanying financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP) for interim financial information, and in management’s opinion, includes all adjustments, consisting of only normal recurring adjustments, necessary for the fair statement of the Company’s financial position, its results of operations, stockholders’ equity and cash flows for the interim periods presented. The results of operations for the three and nine months ended September 30, 2016 are not necessarily indicative of the results to be expected for the full fiscal year or any other period. The accompanying financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on March 14, 2016. There have been no significant changes in the Company’s accounting policies from those disclosed in its Annual Report on Form 10-K filed with the SEC on March 14, 2016. Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Management bases these estimates and assumptions upon historical experience, existing and known circumstances, authoritative accounting pronouncements and other factors that management believes to be reasonable. Significant areas requiring the use of management estimates relate to revenue recognition, inventory and rental asset valuations and write-downs, accounts receivable allowances for bad debts, returns and adjustments, stock compensation expense, impairment assessments, depreciation and amortization, income tax provision and uncertain tax positions, fair value of financial instruments, and fair values of acquired intangibles. Actual results could differ from these estimates. Reclassifications Certain reclassifications have been made to prior years’ financial statements to conform to current period financial statements’ presentation with no effect on previously reported financial position, results of operations or cash flows. These changes consisted of reclassifications to certain line items in the accompanying Statement of Cash Flows and did not change total operating, financing or investing activities as previously reported. Recent accounting pronouncements Income taxes pronouncements: In November 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2015-17, Balance Sheet Classification of Deferred Taxes Revenue recognition pronouncements: In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers In August 2015, the FASB decided to delay the effective date of ASU No. 2014-09 by one year. The FASB also agreed to allow entities to choose to adopt the standard as of the original effective date. As such, the updated standard will be effective for the Company in the first quarter of 2018, with the option to adopt it in the first quarter of 2017. The Company is currently evaluating the impact of the Company’s pending adoption of ASU No. 2014-09 on the Company’s financial statements and has not yet determined the method by which the Company will adopt the standard. In March 2016, the FASB issued ASU No. 2016-08, Revenue with Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus net) In April 2016, the FASB issued ASU No. 2016-10, Revenue with Contracts with Customers: Identifying Performance Obligations and Licensing In May 2016, the FASB issued ASU No. 2016-12, Revenue with Contracts with Customers: Narrow-scope Improvements and Practical Expedients Inventory pronouncements: In July 2015, the FASB issued ASU No. 2015-11, Simplifying the Measurement of Inventory Leases pronouncements: On February 25, 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) Stock compensation pronouncements: In March 2016, the FASB issued ASU No. 2016-09, Compensation – Stock Compensation Financial instruments pronouncements: In June 2016, the FASB issued ASU No. 2016-13, Accounting for Credit Losses (Topic 326) Statement of cash flows pronouncements: In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230) Business segments The Company operates and reports in only one operating and reportable segment – development, manufacturing, marketing, sales, and rental of respiratory products.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	3. Fair value of financial instruments The Company’s financial instruments consist of cash and cash equivalents, marketable securities, accounts receivable, accounts payable and accrued expenses, debt and warrants. The carrying values of cash and cash equivalents, marketable securities, accounts receivable and accounts payable and accrued expenses approximate fair values based on the short-term nature of these financial instruments. The fair value of the Company’s debt approximates carrying value based on the Company’s current incremental borrowing rate for similar types of borrowing arrangements. Imputed interest associated with the Company’s non-interest bearing debt is insignificant and has been appropriately recognized in the respective periods. Fair value accounting ASC 820 —Fair Value Measurements and Disclosures Level input Input definition Level 1 Inputs are unadjusted, quoted prices for identical assets or liabilities in active markets at the measurement date. Level 2 Inputs, other than quoted prices included in Level 1 that are observable for the asset or liability through corroboration with market data at the measurement date. Level 3 Unobservable inputs that reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. The Company obtained the fair value of its available-for-sale investments, which are not in active markets, from a third-party professional pricing service using quoted market prices for identical or comparable instruments, rather than direct observations of quoted prices in active markets. The Company's professional pricing service gathers observable inputs for all of its fixed income securities from a variety of industry data providers (e.g., large custodial institutions) and other third-party sources. Once the observable inputs are gathered, all data points are considered and the fair value is determined. The Company validates the quoted market prices provided by its primary pricing service by comparing their assessment of the fair values against the fair values provided by its investment managers. The Company's investment managers use similar techniques to its professional pricing service to derive pricing as described above. As all significant inputs were observable, derived from observable information in the marketplace or supported by observable levels at which transactions are executed in the marketplace, the Company has classified its available-for-sale investments within Level 2 of the fair value hierarchy. The following table summarizes fair value measurements by level for the assets measured at fair value on a recurring basis for cash, cash equivalents and marketable securities: As of September 30, 2016 Gross Cash Adjusted unrealized and cash Marketable cost losses Fair value equivalents securities Cash $ 43,454 $ — $ 43,454 $ 43,454 $ — Level 1: Money market accounts 39,793 — 39,793 39,793 — Level 2: Certificates of deposit 14,782 — 14,782 2,762 12,020 Corporate bonds 10,321 (10 ) 10,311 — 10,311 Total $ 108,350 $ (10 ) $ 108,340 $ 86,009 $ 22,331 As of December 31, 2015 Gross Cash Adjusted unrealized and cash Marketable cost losses Fair value equivalents securities Cash $ 52,164 $ — $ 52,164 $ 52,164 $ — Level 1: Money market accounts 6,725 — 6,725 6,725 — Level 2: Certificates of deposit 24,047 (37 ) 24,010 7,217 16,793 Total $ 82,936 $ (37 ) $ 82,899 $ 66,106 $ 16,793 The following table summarizes the estimated fair value of the Company’s investments in marketable securities, accounted for as available-for-sale securities and classified by the contractual maturity date of the securities: September 30, 2016 Due within one year $ 15,081 Due in one year through five years 7,250 Total $ 22,331 Derivative instruments and hedging activities The Company transacts business in foreign currencies and has international sales and expenses denominated in foreign currencies, subjecting the Company to foreign currency risk. The Company has entered into foreign currency forward contracts, generally with maturities of twelve months or less, to reduce the volatility of cash flows primarily related to forecasted revenue denominated in certain foreign currencies. These contracts allow the Company to sell Euros in exchange for U.S. dollars at specified contract rates. Forward contracts are used to hedge forecasted sales over specific months. Changes in the fair value of these forward contracts designed as cash flow hedges are recorded as a component of accumulated other comprehensive income (loss) within stockholders’ equity and are recognized in the statements of comprehensive income during the period which approximates the time the corresponding sales occur. The Company may also enter into foreign exchange contracts that are not designated as hedging instruments for financial accounting purposes. These contracts are generally entered into to offset the gains and losses on certain asset and liability balances until the expected time of repayment. Accordingly, any gains or losses resulting from changes in the fair value of the non-designated contracts are reported in other income (expense), net in the statements of comprehensive income. The gains and losses on these contracts generally offset the gains and losses associated with the underlying foreign currency-denominated balances, which are also reported in other income (expense), net. The Company records the assets or liabilities associated with derivative instruments and hedging activities at fair value based on Level 2 inputs in other current assets or other current liabilities, respectively, in the balance sheet. The Company had a receivable of $6 as of September 30, 2016 and a payable of $24 as of December 31, 2015. The Company classifies the foreign currency derivative instruments within Level 2 in the fair value hierarchy as the valuation inputs are based on quoted prices and market observable data of similar instruments. The accounting for gains and losses resulting from changes in fair value depends on the use of the derivative and whether it is designated and qualifies for hedge accounting. The Company documents the hedging relationship and its risk management objective and strategy for undertaking the hedge, the hedging instrument, the hedged transaction, the nature of the risk being hedged, how the hedging instrument’s effectiveness in offsetting the hedged risk will be assessed prospectively and retrospectively, and a description of the method used to measure ineffectiveness. The Company assesses hedge effectiveness and ineffectiveness at a minimum quarterly but may assess it monthly. For derivative instruments that are designed and qualify as part of a cash flow hedging relationship, the effective portion of the gain or loss on the derivative is reported in other comprehensive income (loss) and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness are recognized in current period earnings. The Company will discontinue hedge accounting prospectively when it determines that the derivative is no longer effective in offsetting cash flows attributable to the hedge risk. The cash flow hedge is de-designated because a forecasted transaction is not probable of occurring, or management determines to remove the designation of the cash flow hedge. In all situations in which hedge accounting is discontinued and the derivative remains outstanding, the Company continues to carry the derivative at its fair value on the balance sheet and recognizes any subsequent changes in the fair value in earnings. When it is probable that a forecasted transaction will not occur, the Company will discontinue hedge accounting and recognize immediately in earnings gains and losses that were accumulated in other comprehensive income related to the hedging relationship. Accumulated other comprehensive income (loss) The components of accumulated other comprehensive income (loss), net of tax, were as follows: Unrealized Unrealized Accumulated gains (losses) on gains (losses) other available-for- on cash comprehensive sale investments flow hedges income (loss) Balance as of December 31, 2015 $ (23 ) $ (14 ) $ (37 ) Other comprehensive gain, net of tax 16 27 43 Balance as of September 30, 2016 $ (7 ) $ 13 $ 6 Comprehensive income (loss) is the total net earnings and all other non-owner changes in equity. Except for net income and unrealized gains and losses on cash flow hedges and available-for-sale investments, the Company does not have any transactions or other economic events that qualify as comprehensive income (loss).

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2016
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	4. Balance sheet components Cash, cash equivalents, and marketable securities The Company considers all short-term highly liquid investments with a maturity of three months or less to be cash equivalents. Cash equivalents are recorded at cost plus accrued interest (adjusted cost), which approximates fair value which includes the unrealized gains (losses). Certificates of deposit are included in cash equivalents and marketable securities based on the maturity date of the security. Short-term investments are included in marketable securities in the current period presentation. The Company considers investments with maturities greater than three months to be marketable securities. Investments are classified as available-for-sale and are reported at fair value with unrealized gains or losses, if any, reported, net of tax, in accumulated other comprehensive income (loss). All income generated and realized gains or losses from investments are recorded to other income (expense), net. The Company reviews its investments to identify and evaluate investments that have an indication of possible impairment. Factors considered in determining whether a loss is temporary include the length of time and extent to which fair value has been less than the cost basis, the financial condition and near-term prospects of the investee, and the Company's intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. Credit losses and other-than-temporary impairments are declines in fair value that are not expected to recover and are charged to other income (expense), net. During the three and nine months ended September 30, 2016 and 2015, respectively, no losses were recognized for other-than-temporary impairments. September 30, December 31, Cash and cash equivalents 2016 2015 Cash $ 43,454 $ 52,164 Money market accounts 39,793 6,725 Certificates of deposit 2,762 7,217 Total cash and cash equivalents $ 86,009 $ 66,106 Marketable securities Certificates of deposit $ 12,020 $ 16,793 Corporate bonds 10,311 — Total marketable securities $ 22,331 $ 16,793 Accounts receivable and allowance for bad debts, returns, and adjustments Accounts receivable are customer obligations due under normal sales and rental terms. The Company performs credit evaluations of the customers’ financial condition and generally does not require collateral. The allowance for doubtful accounts is maintained at a level that, in management’s opinion, is adequate to absorb potential losses related to accounts receivable and is based upon the Company’s continuous evaluation of the collectability of outstanding balances. Management’s evaluation takes into consideration such factors as past bad debt experience, economic conditions and information about specific receivables. The Company’s evaluation also considers the age and composition of the outstanding amounts in determining their net realizable value. The allowance for doubtful accounts is based on estimates, and ultimate losses may vary from current estimates. As adjustments to these estimates become necessary, they are reported in earnings in the periods in which they become known. This allowance is increased by bad debt provisions charged to bad debt expense, net of recoveries, in operating expense and is reduced by direct write-offs. The Company generally does not allow returns from providers for reasons not covered under its standard warranty. Therefore, provision for sales returns applies primarily to direct-to-consumer sales. This reserve is calculated based on actual historical return rates under the Company’s 30-day return program and is applied to the related sales revenue for the last month of the quarter reported. The Company also records an allowance for rental revenue adjustments, which is recorded as a reduction of rental revenue and net rental accounts receivable balances. These adjustments result from contractual adjustments, including untimely claims filings, or billings not paid due to another provider performing same or similar functions for the patient in the same period, all of which prevent billed revenue from becoming realizable. The reserve is based on historical revenue adjustments as a percentage of rental revenue billed and unbilled during the related period. When recording the allowance for doubtful accounts, the bad debt expense account (general and administrative expense account) is charged; when recording allowance for sales returns, the sales returns account (contra sales revenue account) is charged; and when recording the allowance for rental reserve adjustments, the rental revenue adjustments account (contra rental revenue account) is charged. As of September 30, 2016 and December 31, 2015, included in accounts receivable on the balance sheets were earned but unbilled receivables of $5,272 and $5,155, respectively. These balances reflect gross unbilled receivables prior to any allowances for adjustments and write-offs. The Company consistently applies its allowance estimation methodology from period-to-period. The Company’s best estimate is made on an accrual basis and adjusted in future periods as required. Any adjustments to the prior period estimates are included in the current period. As additional information becomes known, the Company adjusts its assumptions accordingly to change its estimate of the allowance. Gross accounts receivable balance concentrations by major category as of September 30, 2016 and December 31, 2015 were as follows: September 30, December 31, Gross accounts receivable 2016 2015 Medicare $ 11,204 $ 10,510 Medicaid/other government 555 683 Private insurance 3,312 4,852 Patient responsibility 2,856 3,603 Business-to-business & other receivables 18,698 6,369 Total gross accounts receivable $ 36,625 $ 26,017 Net accounts receivable (gross accounts receivable net of allowances) balance concentrations by major category as of September 30, 2016 and December 31, 2015 were as follows: September 30, December 31, Net accounts receivable 2016 2015 Medicare $ 6,668 $ 7,441 Medicaid/other government 394 550 Private insurance 2,738 3,895 Patient responsibility 1,907 2,060 Business-to-business & other receivables 18,010 5,926 Total net accounts receivable $ 29,717 $ 19,872 The following tables set forth the accounts receivable allowances as of September 30, 2016 and December 31, 2015 : September 30, December 31, Allowances - accounts receivable 2016 2015 Doubtful accounts $ 1,192 $ 1,664 Rental revenue adjustments 5,137 4,115 Sales returns 579 366 Total allowances - accounts receivable $ 6,908 $ 6,145 Concentration of credit risk Financial instruments that potentially subject the Company to concentration of credit risk consist principally of cash, cash equivalents, marketable securities and accounts receivable. At times, cash account balances may be in excess of the amounts insured by the Federal Deposit Insurance Corporation (FDIC). However, management believes the risk of loss to be minimal. The Company performs periodic evaluations of the relative credit standing of these institutions and has not experienced any losses on its cash and cash equivalents to date. The Company has entered into hedging relationships with a single counterparty to offset a portion of the forecasted Euro based revenues. The credit risk has been reduced due to a net settlement arrangement whereby the Company is allowed to net settle transactions with a single net amount payable by one party to the other. Concentration of customers and vendors The Company primarily sells its products to traditional home medical equipment providers, distributors, and resellers in the United States and in foreign countries on a credit basis. The Company primarily sells its products to consumers on a prepayment basis. No single customer represented more than 10% of the Company’s total revenue for the nine months ended September 30, 2016 and September 30, 2015. One customer represented more than 10% of the Company’s total net accounts receivable balance as of September 30, 2016, and no single customer represented more than 10% of the Company’s total net accounts receivable balance as of December 31, 2015. The Company also rents products directly to consumers for insurance reimbursement, which resulted in a customer concentration relating to Medicare’s service reimbursement programs. Medicare’s service reimbursement programs accounted for 71.0% and 75.9% of rental revenue for the three months ended September 30, 2016 and September 30, 2015, respectively, and based on total revenue was 9.5% and 21.5% for the three months ended September 30, 2016 and September 30, 2015, respectively. Medicare’s service reimbursement programs accounted for 71.6% and 74.0% of rental revenue for the nine months ended September 30, 2016 and September 30, 2015, respectively, and based on total revenue was 12.4% and 21.1% for the nine months ended September 30, 2016 and September 30, 2015, respectively. One customer represented more than 10% of the Company’s total revenue for the three months ended September 30, 2016. Accounts receivable balances relating to Medicare’s service reimbursement programs (including held and unbilled, net of allowances) amounted to $6,668 or 22.4% of total net accounts receivable as of September 30, 2016 as compared to $7,441, or 37.4% of total net accounts receivable as of December 31, 2015. The Company currently purchases raw materials from a limited number of vendors, which resulted in a concentration of three major vendors. The three major vendors supply the Company with raw materials used to manufacture the Company’s products. For the nine months ended September 30, 2016, the Company’s three major vendors accounted for 22.0%, 14.9%, and 7.9%, respectively, of total raw material purchases. For the nine months ended September 30, 2015, the Company’s three major vendors accounted for 23.0%, 17.4% and 8.9%, respectively, of total raw material purchases. A portion of revenue is earned from sales outside the United States. Approximately 72.8% and 87.5% of the non-U.S. revenue for the three months ended September 30, 2016 and September 30, 2015, respectively, were invoiced in Euros. Approximately 70.7% and 74.6% of the non-U.S. revenue for the nine months ended September 30, 2016 and September 30, 2015, respectively, were invoiced in Euros. A breakdown of the Company’s revenue from U.S. and non-U.S. sources for the three months and nine months ended September 30, 2016 and September 30, 2015 is as follows: Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 U.S. revenue $ 39,470 $ 32,907 $ 113,963 $ 91,719 Non-U.S. revenue 14,952 7,871 38,015 26,840 Total revenue $ 54,422 $ 40,778 $ 151,978 $ 118,559 Inventories Inventories are stated at the lower of cost or market. Cost is determined using a standard cost method, including material, labor and manufacturing overhead, whereby the standard costs are updated at least quarterly to reflect approximate actual costs using the first-in, first-out (FIFO) method and market represents the lower of replacement cost or estimated net realizable value. The Company records adjustments at least quarterly to inventory for potentially excess, obsolete, slow-moving or impaired items. Inventories consist of the following: September 30, December 31, 2016 2015 Raw materials and work-in-progress $ 14,497 $ 7,097 Finished goods 2,162 1,679 Less: reserves (160 ) (128 ) Inventories $ 16,499 $ 8,648 Property and equipment Property and equipment are stated at cost. Depreciation and amortization are calculated using the straight-line method over the assets’ estimated useful lives as follows: Rental equipment 1.5-5 years Manufacturing equipment and tooling 2-5 years Computer equipment and software 2-3 years Furniture and equipment 3-5 years Leasehold improvements Lesser of estimated useful life or remaining lease term Expenditures for additions, improvements and replacements are capitalized and depreciated to a salvage value of $0. Repair and maintenance costs on rental equipment are included in cost of rental revenue on the statements of comprehensive income. Repair and maintenance expense, which includes labor, parts and freight, for rental equipment was $497 and $686 for the three months ended September 30, 2016 and September 30, 2015, respectively, and $1,930 and $1,897 for the nine months ended September 30, 2016 and September 30, 2015, respectively. Included within property and equipment is construction in process, primarily related to the design and engineering of tooling, jigs and other machinery. In addition, this item also includes computer software or development costs that have been purchased, but have not completed the final configuration process for implementation into the Company’s systems. These items have not been placed in service; therefore, no depreciation or amortization was recognized for these items in the respective periods. Depreciation and amortization expense related to property and equipment and rental equipment are summarized below for the three and nine months ended September 30, 2016 and September 30, 2015, respectively. Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Rental equipment $ 2,878 $ 3,029 $ 8,733 $ 8,929 Other property and equipment 510 510 1,484 1,475 Total depreciation and amortization $ 3,388 $ 3,539 $ 10,217 $ 10,404 Property and equipment and rental equipment with associated accumulated depreciation is summarized below for September 30, 2016 and December 31, 2015, respectively. September 30, December 31, Property and equipment 2016 2015 Rental equipment, net of allowances of $600 and $850, respectively $ 54,684 $ 54,677 Other property and equipment 12,636 11,596 Property and equipment 67,320 66,273 Accumulated depreciation Rental equipment 32,731 28,894 Other property and equipment 7,754 6,699 Accumulated depreciation 40,485 35,593 Net property and equipment Rental equipment 21,953 25,783 Other property and equipment 4,882 4,897 Property and equipment, net $ 26,835 $ 30,680 Long-lived assets The Company accounts for the impairment and disposition of long-lived assets in accordance with ASC 360- Property, Plant, and Equipment Intangible assets There were no impairments recorded related to the Company’s intangible assets during the three months or nine months ended September 30, 2016 and September 30, 2015. Amortization expense for intangible assets for the three months ended September 30, 2016 and September 30, 2015 was $28 and $21, respectively, and for the nine months ended September 30, 2016 and September 30, 2015 was $73 and $64, respectively. The following tables represent the changes in net carrying values of the intangibles as of the respective dates: Average estimated Gross useful lives carrying Accumulated September 30, 2016 (in years) amount amortization Net amount Licenses 10 $ 185 $ 114 $ 71 Patents and websites 5 873 801 72 Commercials 2 286 161 125 Total $ 1,344 $ 1,076 $ 268 Average estimated Gross useful lives carrying Accumulated December 31, 2015 (in years) amount amortization Net amount Licenses 10 $ 185 $ 100 $ 85 Patents and websites 5 873 779 94 Commercials 2 174 124 50 Total $ 1,232 $ 1,003 $ 229 The minimum aggregate amortization expense for intangibles for each of the five succeeding fiscal years is summarized as follows: September 30, 2016 Remaining 3 months of 2016 $ 28 2017 101 2018 86 2019 33 2020 9 Thereafter 11 $ 268 Accounts payable and accrued expenses Accounts payable and accrued expenses as of September 30, 2016 and December 31, 2015 consisted of the following: September 30, December 31, 2016 2015 Accounts payable $ 10,214 $ 7,448 Accrued inventory (in-transit and unvouchered receipts) and trade payables 7,570 3,548 Accrued purchasing card liability 2,000 1,581 Accrued franchise and use taxes 32 45 Other accrued expenses 894 245 Accounts payable and accrued expenses $ 20,710 $ 12,867

Earnings per Share

Earnings per Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings per Share	5. Earnings per share Earnings per share (EPS) is computed in accordance with ASC 260 —Earnings per Share Basic earnings per share is calculated using the Company’s weighted-average outstanding common shares. Diluted earnings per share is calculated using the Company’s weighted-average outstanding common shares including the dilutive effect of stock awards as determined under the treasury stock method. The computation of EPS is as follows: Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Numerator—basic and diluted: Net income $ 3,455 $ 2,696 $ 10,962 $ 7,727 Denominator: Weighted-average common shares - basic common stock 20,157,688 19,428,653 19,986,544 19,303,057 Weighted-average common shares - diluted common stock 21,100,725 20,783,550 20,924,022 20,690,499 Net income per share - basic common stock $ 0.17 $ 0.14 $ 0.55 $ 0.40 Net income per share - diluted common stock $ 0.16 $ 0.13 $ 0.52 $ 0.37 Denominator calculation from basic to diluted: Weighted-average common shares - basic common stock 20,157,688 19,428,653 19,986,544 19,303,057 Warrants — 15,122 — 15,102 Stock options 943,037 1,339,775 937,478 1,372,340 Weighted-average common shares - diluted common stock 21,100,725 20,783,550 20,924,022 20,690,499 Shares excluded from diluted weighted-average shares: Stock options 663,175 627,688 1,284,424 629,136 Shares excluded from diluted weighted-average shares 663,175 627,688 1,284,424 629,136 The computations of diluted net income attributable to common stockholders exclude common stock options which were anti-dilutive for the three months and nine months ended September 30, 2016 and September 30, 2015, respectively.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Long-Term Debt	6. Long-term debt JPMorgan Chase Bank debt As of September 30, 2016 and December 31, 2015, the Company had no outstanding borrowings under its revolving line of credit. Patent purchase obligation The contractual obligations schedule below relates to the acquisition of patents which are reflected in intangible assets and were acquired in 2011. September 30, December 31, 2016 2015 Contractual obligation, bearing imputed interest at prime plus two, quarterly payments of $53 beginning May 2011 through October 2014 and quarterly payments of $81 beginning January 2015 through October 2016 $ 80 $ 315 Less: current maturities (80 ) (315 ) Long-term debt, net of current portion $ — $ — As of September 30, 2016, the minimum aggregate payments due under non-cancelable debt are summarized as follows: September 30, 2016 Remaining 3 months of 2016 $ 80 Total $ 80

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	7. Income taxes The Company accounts for income taxes in accordance with ASC 740 —Income Taxes The Company accounts for uncertainties in income tax in accordance with ASC 740-10 —Accounting for Uncertainty in Income Taxes The Company recognizes interest and penalties on taxes, if any, within its income tax provision. No significant interest or penalties were recognized during the periods presented. The Company operates in multiple states. The statute of limitations has expired for all tax years prior to 2012 for federal and 2011 to 2012 for various state tax purposes. However, the net operating loss generated on the Company’s federal and state tax returns in prior years may be subject to adjustments by the federal and state tax authorities. Income tax expense was $1,994 and $982, an effective tax rate 36.6% and 26.7%, for the three months ended September 30, 2016 and September 30, 2015, respectively. Income tax expense was $5,929 and $3,683, an effective tax rate 35.1% and 32.3%, for the nine months ended September 30, 2016 and September 30, 2015, respectively. The increase in the effective tax rate was primarily due to the tax benefit adjustments that occurred in the third quarter of 2015 partially offset by research and development credits allowed in the third quarter of 2016, but not in the comparative period in 2015.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Stockholders' Equity	8. Stockholders’ equity The Company has a 2012 Equity Incentive Plan (2012 Plan) under which the Company granted options to purchase shares of its common stock. As of September 30, 2016, options to purchase 461,821 shares of common stock remained outstanding under the 2012 Plan. The 2012 Plan was terminated in connection with the Company’s initial public offering, and accordingly, no new options are available for issuance under this plan. The 2012 Plan continues to govern outstanding awards granted thereunder. The Company has a 2002 Stock Incentive Plan (2002 Plan) as amended, under which the Company granted options to purchase shares of its common stock. As of September 30, 2016, options to purchase 161,657 shares of common stock remained outstanding under the 2002 Plan. The 2002 Plan was terminated in March 2012 in connection with the adoption of the 2012 Plan, and, accordingly, no new options are available for issuance under this plan. The 2002 Plan continues to govern outstanding awards granted thereunder. The Company’s board of directors adopted and its stockholders approved a 2014 Equity Incentive Plan (2014 Plan) effective immediately prior to the effectiveness of its initial public offering. The 2014 Plan provides for the grant of incentive stock options, within the meaning of Section 422 of the Internal Revenue Code, to the Company’s employees and any parent and subsidiary corporation’s employees, and for the grant of nonstatutory stock options, restricted stock, restricted stock units, stock appreciation rights, performance units and performance shares to its employees, directors and consultants and its parent and subsidiary corporations’ employees and consultants. As of September 30, 2016, options to purchase 1,875,277 shares of the Company’s common stock were outstanding, and 436,549 shares of common stock remained available for issuance under the 2014 Plan. The shares available for issuance under the 2014 Plan will be increased by any shares returned to the 2002 Plan, 2012 Plan and the 2014 Plan as a result of expiration or termination of awards (provided that the maximum number of shares that may be added to the 2014 Plan pursuant to such previously granted awards under the 2002 Plan and 2012 Plan is 2,328,569 shares). The number of shares available for issuance under the 2014 Plan also is increased annually on the first day of each fiscal year by an amount equal to the least of: • 895,346 shares; • 4% of the outstanding shares of common stock as of the last day of the Company’s immediately preceding fiscal year; or • such other amount as the Company’s board of directors may determine. For 2016, an additional 791,296 shares were added to the 2014 Plan share reserve pursuant to the provision described above. Options typically expire between seven and ten years from the date of grant and vest over one to four year terms. Options have been granted to employees, directors and consultants of the Company, as determined by the board of directors, at the deemed fair market value of the shares underlying the options at the date of grant. The activity for stock options under the Company’s stock plans is as follows: Remaining weighted- Weighted- average Per share average contractual average Price per exercise terms intrinsic Options share price (in years) value Outstanding as of December 31, 2015 2,295,370 $0.60-$46.66 $ 19.36 5.98 $ 21.07 Granted 672,998 44.19-56.72 44.47 Exercised (424,462 ) 0.60-46.66 10.84 Forfeited (44,636 ) 8.37-44.19 27.99 Expired (515 ) 8.70 8.70 Outstanding as of September 30, 2016 2,498,755 0.60-56.72 27.41 5.65 32.49 Vested and exercisable as of September 30, 2016 1,039,364 0.60-56.72 15.63 5.18 44.27 Vested and expected to vest as of September 30, 2016 2,390,297 $0.60-$56.72 $ 27.18 5.63 $ 32.72 The Company’s board of directors adopted and its stockholders approved a 2014 Employee Stock Purchase Plan (ESPP) effective immediately prior to the effectiveness of its initial public offering. The ESPP provides for the grant to all eligible employees an option to purchase stock under the ESPP, within the meaning Section 423 of the Internal Revenue Code. The ESPP permits participants to purchase common stock through payroll deductions of up to 15% of their eligible compensation, which includes a participant’s base straight time gross earnings, incentive compensation, bonuses, overtime and shift premium, but exclusive of payments for equity compensation and other similar compensation. A participant may purchase a maximum of 1,500 shares during a purchase period. Amounts deducted and accumulated by the participant are used to purchase shares of the Company’s common stock at the end of each six-month period. The purchase price of the shares will be 85% of the lower of the fair market value of the Company’s common stock on the first trading day of each offering period or on the exercise date. The offering periods are currently approximately six months in length beginning on the first business day on or after March 1 and September 1 of each year and ending on the first business day on or after September 1 and March 1 approximately six months later. As of September 30, 2016, a total of 438,365 shares of common stock were available for sale pursuant to the ESPP. The number of shares available for sale under the ESPP is increased annually on the first day of each fiscal year by an amount equal to the least of: • 179,069 shares; • 1.5% of the outstanding shares of the Company’s common stock on the last day of the Company’s immediately preceding fiscal year; or • such other amount as may be determined by the administrator. For 2016, an additional 179,069 shares were added to the ESPP share reserve pursuant to the provision described above. Stock-based compensation expense recognized for the three months and nine months ended September 30, 2016 and September 30, 2015 was as follows: Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 Stock-based compensation expense by type of award: Stock option plan awards $ 1,858 $ 941 $ 5,063 $ 2,078 Employee stock purchase plan 95 75 341 265 Total stock-based compensation expense $ 1,953 $ 1,016 $ 5,404 $ 2,343 Employee stock-based compensation expense recognized for the nine months ended September 30, 2016 and September 30, 2015 was calculated based on awards ultimately expected to vest and has been reduced for estimated forfeitures at a rate of 7.3% and 7.5%, respectively, based on the Company’s historical option cancellations. ASC 718 requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. For the three months and nine months ended September 30, 2016 and September 30, 2015, stock-based compensation expense recognized under ASC 718, included in cost of revenues, sales and marketing expense, general and administrative expense, and research and development expense was as follows: Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 Cost of revenue $ 175 $ 128 $ 454 $ 294 Sales and marketing 318 297 859 677 General and administrative 1,237 459 3,530 1,068 Research and development 223 132 561 304 Total stock-based compensation expense $ 1,953 $ 1,016 $ 5,404 $ 2,343 The unrecognized compensation expense related to non-vested share based compensation granted under the Plans as of September 30, 2016 and September 30, 2015 was $17,607 and $11,579, respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2016
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and contingencies Leases The Company leases its offices and certain equipment under operating leases that expire through January 2022. As of September 30, 2016, the minimum aggregate payments due under non-cancelable leases are summarized as follows: September 30, 2016 Remaining 3 months of 2016 $ 291 2017 1,169 2018 1,157 2019 1,155 2020 755 Thereafter 270 $ 4,797 Rent expense of $263 and $221 for the three months ended September 30, 2016 and September 30, 2015, respectively, and $766 and $661 for the nine months ended September 30, 2016 and September 30, 2015, respectively, was included in the accompanying statements of comprehensive income. Purchase obligations The Company had approximately $40,200 of outstanding purchase orders with its outside vendors and suppliers as of September 30, 2016. In addition, the Company entered into agreements for other services. Future commitments under these purchase orders and other agreements do not extend beyond twelve months. Warranty obligation The following table identifies the changes in the Company’s aggregate product warranty liabilities for the nine and twelve-month periods ended September 30, 2016 and December 31, 2015, respectively: September 30, December 31, 2016 2015 Product warranty liability at beginning of period $ 1,973 $ 1,115 Accruals for warranties issued 2,367 1,871 Adjustments related to preexisting warranties (including changes in estimates) 318 510 Settlements made (in cash or in kind) (1,261 ) (1,523 ) Product warranty liability at end of period $ 3,397 $ 1,973 Legislation and HIPAA The healthcare industry is subject to numerous laws and regulations of federal, state and local governments. These laws and regulations include, but are not necessarily limited to, matters such as licensure, accreditation, government healthcare program participation requirements, reimbursement for patient services, and Medicare and Medicaid fraud and abuse. Government activity has continued with respect to investigations and allegations concerning possible violations of fraud and abuse statutes and regulations by healthcare providers. Violations of these laws and regulations could result in expulsion from government healthcare programs together with the imposition of significant fines and penalties, as well as significant repayments for patient services previously billed. The Company believes that it is in compliance in all material respects with applicable fraud and abuse regulations and other applicable government laws and regulations. Compliance with such laws and regulations can be subject to future government review and interpretation as well as regulatory actions unknown or unasserted at this time. The Company believes that it complies in all material respects with the provisions of those regulations that are applicable to the Company’s business. The Health Insurance Portability and Accountability Act of 1996 (HIPAA) assures health insurance portability, reduces healthcare fraud and abuse, guarantees security and privacy of health information, and enforces standards for health information. The Health Information Technology for Economic and Clinical Health Act (HITECH Act) imposes notification requirements of certain security breaches relating to protected health information. The Company may be subject to significant fines and penalties if found not to be compliant with the provisions outlined in the regulations. Legal proceedings Inova Labs lawsuit On November 4, 2011, the Company filed a lawsuit in the United States District Court for the Central District of California against Inova Labs Inc., or Defendant, for infringement of two of the Company’s patents. The case, Inogen Inc. v. Inova Labs Inc., Case No. 8:11-cv-01692-JGB-AN, or the Inova Labs Lawsuit, involves U.S. Patent Nos. 7,841,343, entitled “Systems and Methods For Delivering Therapeutic Gas to Patients”, or the ’343 patent, and 6,605,136 entitled “Pressure Swing Adsorption Process Operation And Optimization”, or the ’136 patent. The Company alleged in the Inova Labs Lawsuit that certain of Defendant’s oxygen concentrators infringe various claims of the ’343 and ’136 patents. The Inova Labs Lawsuit sought damages, injunctive relief, costs and attorneys’ fees. The Defendant answered the complaint, denying infringement and asserting various sets of defenses including non-infringement, invalidity and unenforceability, patent misuse, unclean hands, laches and estoppel. The Defendant also filed counterclaims against the Company alleging patent invalidity, non-infringement and inequitable conduct. The Company denied the allegations in the Defendant’s counterclaims and filed a motion to dismiss Defendant’s inequitable conduct counterclaim. The Defendant filed requests with the U.S. Patent and Trademark Office seeking an inter partes reexamination of the ’343 and ’136 patents. The Defendant also filed a motion to stay the Inova Labs Lawsuit pending outcome of the reexamination. On March 20, 2012, the Court granted the Defendant’s motion to stay the Inova Labs Lawsuit pending outcome of the reexamination and also granted the Company’s motion to dismiss the Defendant’s inequitable conduct counterclaim. On December 7, 2015, the U.S. Patent and Trademark Office issued an inter partes Reexamination Certificate for the ‘343 patent. Reexamination proceedings for the ‘136 patent have not concluded. On February 4, 2016, ResMed Inc. announced the completion of the acquisition of Inova Labs Inc. The parties reached a mutually agreeable settlement in June 2016. On June 30, 2016, the parties filed a Stipulated Dismissal with Prejudice of all claims in this lawsuit and a Joint Motion to Dismiss the reexamination proceeding for the ‘136 patent. The Company recognized a gain of $1,000 related to the settlement during the three months ended June 30, 2016 classified within general and administrative expense and the receivable was recorded in prepaid expenses and other current assets as of June 30, 2016. In addition, the settlement included a gain contingency of $250 for future services and licensing fees charged by the Defendant. The Company received $1,250 on July 26, 2016 finalizing the payment of this settlement. The Company recorded a gain of $72 during the three months ended September 30, 2016 classified within general and administrative expense. The remaining deferred gain contingency of $178 as of September 30, 2016 was recorded within accounts payable and accrued expenses and will be recognized when services are rendered or incurred. The parties are also collaborating on a study of the use of portable oxygen concentrators. Securities class action lawsuit On March 13 and March 19, 2015, plaintiffs Brad Christi and Roger D. Holford each filed, respectively, a lawsuit against Inogen, Raymond Huggenberger, Inogen’s Chief Executive Officer, and Alison Bauerlein, Inogen’s Executive Vice President and Chief Financial Officer, in the United States District Court for the Central District of California on behalf of a purported class of purchasers of the Company’s securities between November 12, 2014 and March 11, 2015. The complaints alleged that Inogen, Mr. Huggenberger and Ms. Bauerlein violated Section 10(b) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, and Rule 10b-5 promulgated thereunder, and that Mr. Huggenberger and Ms. Bauerlein violated Section 20(a) of the Exchange Act. Specifically, the complaints alleged that during the purported class period the Company’s financial statements and disclosures concerning internal controls over financial reporting were materially false and misleading. The complaints sought compensatory damages in an unspecified amount, costs and expenses, including attorneys’ fees and expert fees, prejudgment and post-judgment interest and such other relief as the court deemed proper. On May 7, 2015, plaintiff Roger D. Holford filed a notice of voluntary dismissal without prejudice pursuant to Federal Rule of Civil Procedure Rule 41(a)(1)(A) in the second filed action. On June 29, 2015, plaintiff Brad Christi filed a notice of voluntary dismissal without prejudice pursuant to Federal Rule of Civil Procedure Rule 41(a)(1)(A) in the first filed action. The case was closed by the Court as of June 29, 2015. Separation Design Group lawsuit On October 23, 2015, Separation Design Group IP Holdings, LLC (SDGIP) filed a lawsuit against the Company in the United States District Court for the Central District of California. On December 7, 2015, SDGIP filed a First Amended Complaint in the SDGIP Lawsuit. SDGIP alleges that the Company willfully infringes U.S. Patent Nos. 8,894,751 and 9,199,055, both of which are titled “Ultra Rapid Cycle Portable Oxygen Concentrator.” SDGIP also alleges misappropriation of trade secrets and breach of contract stemming from a meeting in September 2010. The Company never received any communication from SDGIP related to patent infringement, misuse of trade secrets, or breach of the mutual non-disclosure agreement prior to SDGIP filing the lawsuit. SDGIP seeks to recover an unspecified amount of damages (including compensatory and treble damages), costs and expenses (including attorneys’ fees), pre-judgment and post-judgment interest, and other relief that the Court deems proper. SDGIP also seeks a permanent injunction against the Company. The Company has and continues to vigorously contest SDGIP’s claims. The Company has answered SDGIP’s First Amended Complaint, denying SDGIP’s allegations of patent infringement, trade secret misappropriation, and breach of contract and asserting several affirmative defenses. The Company has also filed counterclaims against SDGIP alleging that the patents-in-suit are unenforceable due to inequitable conduct. Labor law dispute On April 13, 2016, Ryan Casper and Shane Hoefer (Plaintiffs) filed a lawsuit against the Company on behalf of themselves and all other similarly situated employees in the Superior Court for Santa Barbara County, California. The complaint alleges failure to pay overtime wages, failure to allow and pay for meal periods, and other alleged violations of California wage and hour law. The Plaintiffs and class members are seeking compensatory damages in the amount of all wages, interest, and penalties allegedly due, as well as liquidated damages, attorney’s fees and other relief. The parties successfully mediated the claims and reached a settlement in April 2016. While the Company disputes the claims, it agreed to the settlement with no admission of liability to avoid the risks and costs associated with litigating the claims. As of September 30, 2016, the Company had accrued approximately $980 for the settlement costs within accounts payable and accrued expenses. On August 2, 2016, the Court granted preliminary approval of the settlement. The parties anticipate final approval of the settlement in late November 2016, and distribution of the settlement funds in December 2016. CAIRE Inc. lawsuit On September 12, 2016, CAIRE Inc. (CAIRE) filed a lawsuit in the United States District Court for the Northern District of Georgia against the Company. CAIRE alleges that the Company infringes U.S. Patent No. 6,949,133, entitled “Portable Oxygen Concentrator.” CAIRE alleges willful infringement and seeks damages, injunctive relief, pre-judgment and post-judgment interest, costs, and attorneys’ fees. The Company denies CAIRE’s allegations and plans to vigorously contest CAIRE’s claims. The Company’s response to CAIRE’s complaint is due in early November 2016. Other legal proceedings The Company is party to various legal proceedings arising in the normal course of business. The Company carries insurance, subject to specified deductibles under the policies, to protect against losses from certain types of legal claims. At this time, the Company does not anticipate that any of these other proceedings will have a material adverse effect on the Company’s business. Regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources, and other factors .

Foreign Currency Exchange Contr

Foreign Currency Exchange Contracts and Hedging	9 Months Ended
	Sep. 30, 2016
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Foreign currency exchange contracts and hedging	10. Foreign currency exchange contracts and hedging As of September 30, 2016, the Company’s total non-designated and designated derivative contracts had notional amounts totaling approximately $736 and $2,839, respectively. These contracts were comprised of offsetting contracts with the same counterparty, each expires within one to six months of September 30, 2016, and the designated contracts had an unrealized gain of approximately $27, net of tax, during the nine months ended September 30, 2016. The nonperformance risk of the Company and the counterparty did not have a material impact on the fair value of the derivatives. During the nine months ended September 30, 2016, the ineffective portion relating to these hedges was immaterial and the hedges remained effective through their respective settlement dates. As of September 30, 2016, the Company had fourteen designated hedges and four non-designated hedges.

Basis of Presentation and Sum18

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Use of estimates	Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Management bases these estimates and assumptions upon historical experience, existing and known circumstances, authoritative accounting pronouncements and other factors that management believes to be reasonable. Significant areas requiring the use of management estimates relate to revenue recognition, inventory and rental asset valuations and write-downs, accounts receivable allowances for bad debts, returns and adjustments, stock compensation expense, impairment assessments, depreciation and amortization, income tax provision and uncertain tax positions, fair value of financial instruments, and fair values of acquired intangibles. Actual results could differ from these estimates.
Reclassifications	Reclassifications Certain reclassifications have been made to prior years’ financial statements to conform to current period financial statements’ presentation with no effect on previously reported financial position, results of operations or cash flows. These changes consisted of reclassifications to certain line items in the accompanying Statement of Cash Flows and did not change total operating, financing or investing activities as previously reported.
Recent Accounting Pronouncements	Recent accounting pronouncements Income taxes pronouncements: In November 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2015-17, Balance Sheet Classification of Deferred Taxes Revenue recognition pronouncements: In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers In August 2015, the FASB decided to delay the effective date of ASU No. 2014-09 by one year. The FASB also agreed to allow entities to choose to adopt the standard as of the original effective date. As such, the updated standard will be effective for the Company in the first quarter of 2018, with the option to adopt it in the first quarter of 2017. The Company is currently evaluating the impact of the Company’s pending adoption of ASU No. 2014-09 on the Company’s financial statements and has not yet determined the method by which the Company will adopt the standard. In March 2016, the FASB issued ASU No. 2016-08, Revenue with Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus net) In April 2016, the FASB issued ASU No. 2016-10, Revenue with Contracts with Customers: Identifying Performance Obligations and Licensing In May 2016, the FASB issued ASU No. 2016-12, Revenue with Contracts with Customers: Narrow-scope Improvements and Practical Expedients Inventory pronouncements: In July 2015, the FASB issued ASU No. 2015-11, Simplifying the Measurement of Inventory Leases pronouncements: On February 25, 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) Stock compensation pronouncements: In March 2016, the FASB issued ASU No. 2016-09, Compensation – Stock Compensation Financial instruments pronouncements: In June 2016, the FASB issued ASU No. 2016-13, Accounting for Credit Losses (Topic 326) Statement of cash flows pronouncements: In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230)
Business Segments	Business segments The Company operates and reports in only one operating and reportable segment – development, manufacturing, marketing, sales, and rental of respiratory products.

Fair Value of Financial Instr19

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Summary of Fair Value Assets Measured on Recurring Basis for Cash, Cash Equivalents and Marketable Securities	The following table summarizes fair value measurements by level for the assets measured at fair value on a recurring basis for cash, cash equivalents and marketable securities: As of September 30, 2016 Gross Cash Adjusted unrealized and cash Marketable cost losses Fair value equivalents securities Cash $ 43,454 $ — $ 43,454 $ 43,454 $ — Level 1: Money market accounts 39,793 — 39,793 39,793 — Level 2: Certificates of deposit 14,782 — 14,782 2,762 12,020 Corporate bonds 10,321 (10 ) 10,311 — 10,311 Total $ 108,350 $ (10 ) $ 108,340 $ 86,009 $ 22,331 As of December 31, 2015 Gross Cash Adjusted unrealized and cash Marketable cost losses Fair value equivalents securities Cash $ 52,164 $ — $ 52,164 $ 52,164 $ — Level 1: Money market accounts 6,725 — 6,725 6,725 — Level 2: Certificates of deposit 24,047 (37 ) 24,010 7,217 16,793 Total $ 82,936 $ (37 ) $ 82,899 $ 66,106 $ 16,793
Summary of Estimated Fair Value of Company's Investments in Marketable Debt Securities, Accounted for as Available-for-Sale Securities	The following table summarizes the estimated fair value of the Company’s investments in marketable securities, accounted for as available-for-sale securities and classified by the contractual maturity date of the securities: September 30, 2016 Due within one year $ 15,081 Due in one year through five years 7,250 Total $ 22,331
Summary of Components of Accumulated Other Comprehensive Income (Loss), Net of Tax	The components of accumulated other comprehensive income (loss), net of tax, were as follows: Unrealized Unrealized Accumulated gains (losses) on gains (losses) other available-for- on cash comprehensive sale investments flow hedges income (loss) Balance as of December 31, 2015 $ (23 ) $ (14 ) $ (37 ) Other comprehensive gain, net of tax 16 27 43 Balance as of September 30, 2016 $ (7 ) $ 13 $ 6

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2016
Balance Sheet Related Disclosures [Abstract]
Summary of Cash, Cash Equivalents and Short-term Investments	Cash, cash equivalents and marketable securities consist of the following: September 30, December 31, Cash and cash equivalents 2016 2015 Cash $ 43,454 $ 52,164 Money market accounts 39,793 6,725 Certificates of deposit 2,762 7,217 Total cash and cash equivalents $ 86,009 $ 66,106 Marketable securities Certificates of deposit $ 12,020 $ 16,793 Corporate bonds 10,311 — Total marketable securities $ 22,331 $ 16,793
Schedule of Gross Accounts Receivable Balance Concentrations by Major Category	Gross accounts receivable balance concentrations by major category as of September 30, 2016 and December 31, 2015 were as follows: September 30, December 31, Gross accounts receivable 2016 2015 Medicare $ 11,204 $ 10,510 Medicaid/other government 555 683 Private insurance 3,312 4,852 Patient responsibility 2,856 3,603 Business-to-business & other receivables 18,698 6,369 Total gross accounts receivable $ 36,625 $ 26,017
Schedule of Net Accounts Receivable Balance Concentrations by Major Category	Net accounts receivable (gross accounts receivable net of allowances) balance concentrations by major category as of September 30, 2016 and December 31, 2015 were as follows: September 30, December 31, Net accounts receivable 2016 2015 Medicare $ 6,668 $ 7,441 Medicaid/other government 394 550 Private insurance 2,738 3,895 Patient responsibility 1,907 2,060 Business-to-business & other receivables 18,010 5,926 Total net accounts receivable $ 29,717 $ 19,872
Schedule of Allowances for Accounts Receivable	The following tables set forth the accounts receivable allowances as of September 30, 2016 and December 31, 2015 : September 30, December 31, Allowances - accounts receivable 2016 2015 Doubtful accounts $ 1,192 $ 1,664 Rental revenue adjustments 5,137 4,115 Sales returns 579 366 Total allowances - accounts receivable $ 6,908 $ 6,145
Breakdown of Company's Revenue from U.S. and Non-U.S. Sources	A portion of revenue is earned from sales outside the United States. Approximately 72.8% and 87.5% of the non-U.S. revenue for the three months ended September 30, 2016 and September 30, 2015, respectively, were invoiced in Euros. Approximately 70.7% and 74.6% of the non-U.S. revenue for the nine months ended September 30, 2016 and September 30, 2015, respectively, were invoiced in Euros. A breakdown of the Company’s revenue from U.S. and non-U.S. sources for the three months and nine months ended September 30, 2016 and September 30, 2015 is as follows: Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 U.S. revenue $ 39,470 $ 32,907 $ 113,963 $ 91,719 Non-U.S. revenue 14,952 7,871 38,015 26,840 Total revenue $ 54,422 $ 40,778 $ 151,978 $ 118,559
Schedule of Inventories	Inventories consist of the following: September 30, December 31, 2016 2015 Raw materials and work-in-progress $ 14,497 $ 7,097 Finished goods 2,162 1,679 Less: reserves (160 ) (128 ) Inventories $ 16,499 $ 8,648
Computation of Depreciation and Amortization using Straight Line Method Over Estimated Useful Lives of Assets	Property and equipment are stated at cost. Depreciation and amortization are calculated using the straight-line method over the assets’ estimated useful lives as follows: Rental equipment 1.5-5 years Manufacturing equipment and tooling 2-5 years Computer equipment and software 2-3 years Furniture and equipment 3-5 years Leasehold improvements Lesser of estimated useful life or remaining lease term
Summary of Depreciation and Amortization Expense of Property and Equipment and Rental Equipment	Depreciation and amortization expense related to property and equipment and rental equipment are summarized below for the three and nine months ended September 30, 2016 and September 30, 2015, respectively. Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Rental equipment $ 2,878 $ 3,029 $ 8,733 $ 8,929 Other property and equipment 510 510 1,484 1,475 Total depreciation and amortization $ 3,388 $ 3,539 $ 10,217 $ 10,404
Summary of Property Plant and Equipment and Rental Equipment with Associated Accumulated Depreciation	Property and equipment and rental equipment with associated accumulated depreciation is summarized below for September 30, 2016 and December 31, 2015, respectively. September 30, December 31, Property and equipment 2016 2015 Rental equipment, net of allowances of $600 and $850, respectively $ 54,684 $ 54,677 Other property and equipment 12,636 11,596 Property and equipment 67,320 66,273 Accumulated depreciation Rental equipment 32,731 28,894 Other property and equipment 7,754 6,699 Accumulated depreciation 40,485 35,593 Net property and equipment Rental equipment 21,953 25,783 Other property and equipment 4,882 4,897 Property and equipment, net $ 26,835 $ 30,680
Summary of Intangible Assets	The following tables represent the changes in net carrying values of the intangibles as of the respective dates: Average estimated Gross useful lives carrying Accumulated September 30, 2016 (in years) amount amortization Net amount Licenses 10 $ 185 $ 114 $ 71 Patents and websites 5 873 801 72 Commercials 2 286 161 125 Total $ 1,344 $ 1,076 $ 268 Average estimated Gross useful lives carrying Accumulated December 31, 2015 (in years) amount amortization Net amount Licenses 10 $ 185 $ 100 $ 85 Patents and websites 5 873 779 94 Commercials 2 174 124 50 Total $ 1,232 $ 1,003 $ 229
Schedule of Minimum Aggregate Amortization Expense for Intangibles	The minimum aggregate amortization expense for intangibles for each of the five succeeding fiscal years is summarized as follows: September 30, 2016 Remaining 3 months of 2016 $ 28 2017 101 2018 86 2019 33 2020 9 Thereafter 11 $ 268
Schedule of Accounts Payable and Accrued Expenses	Accounts payable and accrued expenses as of September 30, 2016 and December 31, 2015 consisted of the following: September 30, December 31, 2016 2015 Accounts payable $ 10,214 $ 7,448 Accrued inventory (in-transit and unvouchered receipts) and trade payables 7,570 3,548 Accrued purchasing card liability 2,000 1,581 Accrued franchise and use taxes 32 45 Other accrued expenses 894 245 Accounts payable and accrued expenses $ 20,710 $ 12,867

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Computation of Earnings Per Share	The computation of EPS is as follows: Three months ended September 30, Nine months ended September 30, 2016 2015 2016 2015 Numerator—basic and diluted: Net income $ 3,455 $ 2,696 $ 10,962 $ 7,727 Denominator: Weighted-average common shares - basic common stock 20,157,688 19,428,653 19,986,544 19,303,057 Weighted-average common shares - diluted common stock 21,100,725 20,783,550 20,924,022 20,690,499 Net income per share - basic common stock $ 0.17 $ 0.14 $ 0.55 $ 0.40 Net income per share - diluted common stock $ 0.16 $ 0.13 $ 0.52 $ 0.37 Denominator calculation from basic to diluted: Weighted-average common shares - basic common stock 20,157,688 19,428,653 19,986,544 19,303,057 Warrants — 15,122 — 15,102 Stock options 943,037 1,339,775 937,478 1,372,340 Weighted-average common shares - diluted common stock 21,100,725 20,783,550 20,924,022 20,690,499 Shares excluded from diluted weighted-average shares: Stock options 663,175 627,688 1,284,424 629,136 Shares excluded from diluted weighted-average shares 663,175 627,688 1,284,424 629,136

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	The contractual obligations schedule below relates to the acquisition of patents which are reflected in intangible assets and were acquired in 2011. September 30, December 31, 2016 2015 Contractual obligation, bearing imputed interest at prime plus two, quarterly payments of $53 beginning May 2011 through October 2014 and quarterly payments of $81 beginning January 2015 through October 2016 $ 80 $ 315 Less: current maturities (80 ) (315 ) Long-term debt, net of current portion $ — $ —
Schedule of Minimum Aggregate Payments Due Under Non-Cancelable Debt	As of September 30, 2016, the minimum aggregate payments due under non-cancelable debt are summarized as follows: September 30, 2016 Remaining 3 months of 2016 $ 80 Total $ 80

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Summary of Stock Options Activity	The activity for stock options under the Company’s stock plans is as follows: Remaining weighted- Weighted- average Per share average contractual average Price per exercise terms intrinsic Options share price (in years) value Outstanding as of December 31, 2015 2,295,370 $0.60-$46.66 $ 19.36 5.98 $ 21.07 Granted 672,998 44.19-56.72 44.47 Exercised (424,462 ) 0.60-46.66 10.84 Forfeited (44,636 ) 8.37-44.19 27.99 Expired (515 ) 8.70 8.70 Outstanding as of September 30, 2016 2,498,755 0.60-56.72 27.41 5.65 32.49 Vested and exercisable as of September 30, 2016 1,039,364 0.60-56.72 15.63 5.18 44.27 Vested and expected to vest as of September 30, 2016 2,390,297 $0.60-$56.72 $ 27.18 5.63 $ 32.72
Summary of Stock-based Compensation Expense	Stock-based compensation expense recognized for the three months and nine months ended September 30, 2016 and September 30, 2015 was as follows: Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 Stock-based compensation expense by type of award: Stock option plan awards $ 1,858 $ 941 $ 5,063 $ 2,078 Employee stock purchase plan 95 75 341 265 Total stock-based compensation expense $ 1,953 $ 1,016 $ 5,404 $ 2,343 For the three months and nine months ended September 30, 2016 and September 30, 2015, stock-based compensation expense recognized under ASC 718, included in cost of revenues, sales and marketing expense, general and administrative expense, and research and development expense was as follows: Three months ended Nine months ended September 30, September 30, 2016 2015 2016 2015 Cost of revenue $ 175 $ 128 $ 454 $ 294 Sales and marketing 318 297 859 677 General and administrative 1,237 459 3,530 1,068 Research and development 223 132 561 304 Total stock-based compensation expense $ 1,953 $ 1,016 $ 5,404 $ 2,343

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2016
Commitments And Contingencies Disclosure [Abstract]
Minimum Aggregate Payments Due under Non-Cancelable Leases	The Company leases its offices and certain equipment under operating leases that expire through January 2022. As of September 30, 2016, the minimum aggregate payments due under non-cancelable leases are summarized as follows: September 30, 2016 Remaining 3 months of 2016 $ 291 2017 1,169 2018 1,157 2019 1,155 2020 755 Thereafter 270 $ 4,797
Schedule of Changes in Aggregate Product Warranty Liabilities	The following table identifies the changes in the Company’s aggregate product warranty liabilities for the nine and twelve-month periods ended September 30, 2016 and December 31, 2015, respectively: September 30, December 31, 2016 2015 Product warranty liability at beginning of period $ 1,973 $ 1,115 Accruals for warranties issued 2,367 1,871 Adjustments related to preexisting warranties (including changes in estimates) 318 510 Settlements made (in cash or in kind) (1,261 ) (1,523 ) Product warranty liability at end of period $ 3,397 $ 1,973

Business Overview - Additional

Business Overview - Additional Information (Details)	9 Months Ended
	Sep. 30, 2016Customerlb
Business Overview Disclosures [Line Items]
Percentage of patients using portable oxygen concentrators	8.00%
One G4
Business Overview Disclosures [Line Items]
Weight of oxygen portable device	2.8
One G3
Business Overview Disclosures [Line Items]
Weight of oxygen portable device	4.8
One G2
Business Overview Disclosures [Line Items]
Weight of oxygen portable device	7
Maximum | One G4
Business Overview Disclosures [Line Items]
Estimated battery life of portable oxygen concentrator	2 hours 30 minutes
Maximum | One G3
Business Overview Disclosures [Line Items]
Estimated battery life of portable oxygen concentrator	5 hours
Maximum | One G2
Business Overview Disclosures [Line Items]
Estimated battery life of portable oxygen concentrator	5 hours
Minimum | Inogen One
Business Overview Disclosures [Line Items]
Number of customers served over several years | Customer	196,000

Basis of Presentation and Sum26

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)	9 Months Ended
	Sep. 30, 2016Segment
Accounting Policies [Abstract]
Number of operating segments	1
Number of reportable segments	1

Fair Value of Financial Instr27

Fair Value of Financial Instruments - Summary of Fair Value Assets Measured on Recurring Basis for Cash, Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	$ 22,331	$ 16,793
Fair Value Measurements Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Adjusted cost	108,350	82,936
Gross unrealized losses	(10)	(37)
Fair value	108,340	82,899
Cash and cash equivalents	86,009	66,106
Marketable securities	22,331	16,793
Fair Value Measurements Recurring | Cash
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Adjusted cost	43,454	52,164
Fair value	43,454	52,164
Cash and cash equivalents	43,454	52,164
Fair Value Measurements Recurring | Level 1 | Money Market Accounts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Adjusted cost	39,793	6,725
Fair value	39,793	6,725
Cash and cash equivalents	39,793	6,725
Fair Value Measurements Recurring | Level 2 | Certificates Of Deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Adjusted cost	14,782	24,047
Gross unrealized losses		(37)
Fair value	14,782	24,010
Cash and cash equivalents	2,762	7,217
Marketable securities	12,020	$ 16,793
Fair Value Measurements Recurring | Level 2 | Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Adjusted cost	10,321
Gross unrealized losses	(10)
Fair value	10,311
Marketable securities	$ 10,311

Fair Value of Financial Instr28

Fair Value of Financial Instruments - Summary of Estimated Fair Value of Company's Investments in Marketable Securities, Accounted for as Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Available For Sale Securities [Abstract]
Due within one year	$ 15,081
Due in one year through five years	7,250
Total	$ 22,331	$ 16,793

Fair Value of Financial Instr29

Fair Value of Financial Instruments - Additional Information (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Accounts receivable, net	$ 29,717	$ 19,872
Forward Contracts
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Payable		$ 24
Accounts receivable, net	$ 6

Fair Value of Financial Instr30

Fair Value of Financial Instruments - Summary of Components of Accumulated Other Comprehensive Income (Loss), Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		$ (37)
Other comprehensive gain, net of tax	$ 8	43
Ending Balance	6	6
Unrealized Gains (Losses) on Available-for-sale Investments
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		(23)
Other comprehensive gain, net of tax		16
Ending Balance	(7)	(7)
Unrealized gains (losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance		(14)
Other comprehensive gain, net of tax		27
Ending Balance	$ 13	$ 13

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Cash, Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Cash and cash equivalents
Cash	$ 43,454	$ 52,164
Money market accounts	39,793	6,725
Total cash and cash equivalents	86,009	66,106	$ 55,090	$ 56,836
Marketable securities
Marketable securities	22,331	16,793
Cash Equivalents
Cash and cash equivalents
Certificates of deposit	2,762	7,217
Certificates Of Deposit
Marketable securities
Marketable securities	12,020	$ 16,793
Corporate Bonds
Marketable securities
Marketable securities	$ 10,311

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016USD ($)Customer	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)Customer	Sep. 30, 2015USD ($)Customer	Dec. 31, 2015USD ($)Customer
Schedule Of Balance Sheet Components [Line Items]
Unbilled Receivables	$ 5,272,000		$ 5,272,000		$ 5,155,000
Accounts Receivable Net Current	$ 29,717,000		$ 29,717,000		19,872,000
Percentage of Non-US revenue invoiced in Euros	72.80%	87.50%	70.70%	74.60%
Salvage value of expenditures for additions, improvements and replacements	$ 0		$ 0
Repairs and maintenance expense	497,000	$ 686,000	1,930,000	$ 1,897,000
Depreciation and amortization	3,388,000	3,539,000	10,217,000	10,404,000
Impairments of long-lived assets	0	0	0	0
Impairment of finite lived intangible assets	0	0	0	0
Amortization of intangible assets	28,000	$ 21,000	73,000	64,000
Construction in Process and Computer Software or Development Cost
Schedule Of Balance Sheet Components [Line Items]
Depreciation and amortization			0	$ 0
Customer Concentration Risk
Schedule Of Balance Sheet Components [Line Items]
Accounts Receivable Net Current	$ 6,668,000		$ 6,668,000		$ 7,441,000
Sales Revenue, Net | Customer Concentration Risk
Schedule Of Balance Sheet Components [Line Items]
Number of customers | Customer	1		0	0
Concentration risk, percentage	9.50%	21.50%	12.40%	21.10%
Net Accounts Receivable | Customer Concentration Risk
Schedule Of Balance Sheet Components [Line Items]
Number of customers | Customer			1		0
Concentration risk, percentage			22.40%		37.40%
Sales Revenue, Services, Net | Customer Concentration Risk
Schedule Of Balance Sheet Components [Line Items]
Concentration risk, percentage	71.00%	75.90%	71.60%	74.00%
Raw materials | Supplier Concentration Risk | Vendor one
Schedule Of Balance Sheet Components [Line Items]
Concentration risk, percentage			22.00%	23.00%
Raw materials | Supplier Concentration Risk | Vendor two
Schedule Of Balance Sheet Components [Line Items]
Concentration risk, percentage			14.90%	17.40%
Raw materials | Supplier Concentration Risk | Vendor three
Schedule Of Balance Sheet Components [Line Items]
Concentration risk, percentage			7.90%	8.90%

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Gross Accounts Receivable Balance Concentrations by Major Category (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Gross accounts receivable	$ 36,625	$ 26,017
Medicare
Accounts Notes And Loans Receivable [Line Items]
Gross accounts receivable	11,204	10,510
Medicaid Or Other Government
Accounts Notes And Loans Receivable [Line Items]
Gross accounts receivable	555	683
Private Insurance
Accounts Notes And Loans Receivable [Line Items]
Gross accounts receivable	3,312	4,852
Patient Responsibility
Accounts Notes And Loans Receivable [Line Items]
Gross accounts receivable	2,856	3,603
Business To Business And Other Receivables
Accounts Notes And Loans Receivable [Line Items]
Gross accounts receivable	$ 18,698	$ 6,369

Balance Sheet Components - Sc34

Balance Sheet Components - Schedule of Net Accounts Receivable Balance Concentrations by Major Category (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accounts Notes And Loans Receivable [Line Items]
Accounts receivable, net	$ 29,717	$ 19,872
Medicare
Accounts Notes And Loans Receivable [Line Items]
Accounts receivable, net	6,668	7,441
Medicaid Or Other Government
Accounts Notes And Loans Receivable [Line Items]
Accounts receivable, net	394	550
Private Insurance
Accounts Notes And Loans Receivable [Line Items]
Accounts receivable, net	2,738	3,895
Patient Responsibility
Accounts Notes And Loans Receivable [Line Items]
Accounts receivable, net	1,907	2,060
Business To Business And Other Receivables
Accounts Notes And Loans Receivable [Line Items]
Accounts receivable, net	$ 18,010	$ 5,926

Balance Sheet Components - Sc35

Balance Sheet Components - Schedule of Allowances for Accounts Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Allowances - accounts receivable
Doubtful accounts	$ 1,192	$ 1,664
Rental revenue adjustments	5,137	4,115
Sales returns	579	366
Total allowances - accounts receivable	$ 6,908	$ 6,145

Balance Sheet Components - Brea

Balance Sheet Components - Breakdown of the Company Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Concentration Risk [Line Items]
Revenues	$ 54,422	$ 40,778	$ 151,978	$ 118,559
U.S. revenue
Concentration Risk [Line Items]
Revenues	39,470	32,907	113,963	91,719
Non-U.S. revenue
Concentration Risk [Line Items]
Revenues	$ 14,952	$ 7,871	$ 38,015	$ 26,840

Balance Sheet Components - Sc37

Balance Sheet Components - Schedule of Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Inventory Disclosure [Abstract]
Raw materials and work-in-progress	$ 14,497	$ 7,097
Finished goods	2,162	1,679
Less: reserves	(160)	(128)
Inventories	$ 16,499	$ 8,648

Balance Sheet Components - Comp

Balance Sheet Components - Computation of Depreciation and Amortization Using Straight Line Method Over Estimated Useful Lives of Assets (Details)	9 Months Ended
	Sep. 30, 2016
Equipment | Minimum
Property Plant And Equipment [Line Items]
Property Plant And Equipment Useful Life	1 year 6 months
Equipment | Maximum
Property Plant And Equipment [Line Items]
Property Plant And Equipment Useful Life	5 years
Manufacturing equipment and tooling | Minimum
Property Plant And Equipment [Line Items]
Property Plant And Equipment Useful Life	2 years
Manufacturing equipment and tooling | Maximum
Property Plant And Equipment [Line Items]
Property Plant And Equipment Useful Life	5 years
Computer equipment and software | Minimum
Property Plant And Equipment [Line Items]
Property Plant And Equipment Useful Life	2 years
Computer equipment and software | Maximum
Property Plant And Equipment [Line Items]
Property Plant And Equipment Useful Life	3 years
Furniture and equipment | Minimum
Property Plant And Equipment [Line Items]
Property Plant And Equipment Useful Life	3 years
Furniture and equipment | Maximum
Property Plant And Equipment [Line Items]
Property Plant And Equipment Useful Life	5 years
Leasehold improvements
Property Plant And Equipment [Line Items]
Property Plant And Equipment Useful Life	Lesser of estimated useful life or remaining lease term

Balance Sheet Components - Su39

Balance Sheet Components - Summary of Depreciation and Amortization Expense of Property and Equipment and Rental Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Property Plant And Equipment [Line Items]
Depreciation	$ 2,878	$ 3,029	$ 8,733	$ 8,929
Depreciation and amortization	3,388	3,539	10,217	10,404
Equipment
Property Plant And Equipment [Line Items]
Depreciation	2,878	3,029	8,733	8,929
Other property and equipment
Property Plant And Equipment [Line Items]
Depreciation and amortization	$ 510	$ 510	$ 1,484	$ 1,475

Balance Sheet Components - Su40

Balance Sheet Components - Summary of Property Plant and Equipment and Rental Equipment with Associated Accumulated Depreciation (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Property Plant And Equipment [Line Items]
Property and equipment	$ 67,320	$ 66,273
Accumulated depreciation	40,485	35,593
Property and equipment, net	26,835	30,680
Equipment
Property Plant And Equipment [Line Items]
Property and equipment	54,684	54,677
Accumulated depreciation	32,731	28,894
Property and equipment, net	21,953	25,783
Other property and equipment
Property Plant And Equipment [Line Items]
Property and equipment	12,636	11,596
Accumulated depreciation	7,754	6,699
Property and equipment, net	$ 4,882	$ 4,897

Balance Sheet Components - Su41

Balance Sheet Components - Summary of Property Plant and Equipment and Rental Equipment with Associated Accumulated Depreciation (Parenthetical) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Rental equipment, allowance	$ 600	$ 850

Balance Sheet Components - Su42

Balance Sheet Components - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 1,344	$ 1,232
Accumulated amortization	1,076	1,003
Net amount	$ 268	$ 229
Licenses
Finite Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets	10 years	10 years
Gross carrying amount	$ 185	$ 185
Accumulated amortization	114	100
Net amount	$ 71	$ 85
Patents And Websites
Finite Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets	5 years	5 years
Gross carrying amount	$ 873	$ 873
Accumulated amortization	801	779
Net amount	$ 72	$ 94
Commercial
Finite Lived Intangible Assets [Line Items]
Estimated useful life of intangible assets	2 years	2 years
Gross carrying amount	$ 286	$ 174
Accumulated amortization	161	124
Net amount	$ 125	$ 50

Balance Sheet Components - Sc43

Balance Sheet Components - Schedule of Minimum Aggregate Amortization Expense for Intangibles (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Remaining 3 months of 2016	$ 28
2,017	101
2,018	86
2,019	33
2,020	9
Thereafter	11
Net amount	$ 268	$ 229

Balance Sheet Components - Sc44

Balance Sheet Components - Schedule of Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Payables And Accruals [Abstract]
Accounts payable	$ 10,214	$ 7,448
Accrued inventory (in-transit and unvouchered receipts) and trade payables	7,570	3,548
Accrued purchasing card liability	2,000	1,581
Accrued franchise and use taxes	32	45
Other accrued expenses	894	245
Accounts payable and accrued expenses	$ 20,710	$ 12,867

Earnings per Share - Computatio

Earnings per Share - Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator—basic and diluted:
Net income	$ 3,455	$ 2,696	$ 10,962	$ 7,727
Denominator:
Weighted-average common shares - basic common stock	20,157,688	19,428,653	19,986,544	19,303,057
Weighted-average common shares - diluted common stock	21,100,725	20,783,550	20,924,022	20,690,499
Net income per share - basic common stock	$ 0.17	$ 0.14	$ 0.55	$ 0.40
Net income per share - diluted common stock	$ 0.16	$ 0.13	$ 0.52	$ 0.37
Weighted-average number of shares used in calculating net income per share attributable to common stockholders:
Weighted-average common shares - basic common stock	20,157,688	19,428,653	19,986,544	19,303,057
Warrants		15,122		15,102
Stock options	943,037	1,339,775	937,478	1,372,340
Weighted-average common shares - diluted common stock	21,100,725	20,783,550	20,924,022	20,690,499
Shares excluded from diluted weighted-average shares:
Shares excluded from diluted weighted-average shares	663,175	627,688	1,284,424	629,136
Stock options
Shares excluded from diluted weighted-average shares:
Shares excluded from diluted weighted-average shares	663,175	627,688	1,284,424	629,136

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Debt Disclosure [Abstract]
Line of credit, outstanding borrowings	$ 0	$ 0

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Long-term debt	$ 80
Less: current maturities	(80)	$ (315)
Contractual Obligation
Debt Instrument [Line Items]
Long-term debt	$ 80	$ 315

Long-Term Debt - Schedule of 48

Long-Term Debt - Schedule of Long-Term Debt (Parenthetical) (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
May 2011 Through October 2014
Debt Instrument [Line Items]
Long-term debt, quarterly payments	$ 53
January 2015 through October 2016
Debt Instrument [Line Items]
Long-term debt, quarterly payments	$ 81

Long-Term Debt - Schedule of Mi

Long-Term Debt - Schedule of Minimum Aggregate Payments due under Non-Cancelable Debt (Details) $ in Thousands	Sep. 30, 2016USD ($)
Debt Disclosure [Abstract]
Remaining 3 months of 2016	$ 80
Long-term debt	$ 80

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, interest or penalties recognized			$ 0	$ 0
Income tax expense (benefit)	$ 1,994,000	$ 982,000	$ 5,929,000	$ 3,683,000
Effective income tax rate	36.60%	26.70%	35.10%	32.30%

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Class Of Stock [Line Items]
Rate of reduced stock-based compensation expense for estimated forfeiture	7.30%	7.50%
Share-based compensation, unrecognized expense, nonvested granted awards	$ 17,607	$ 11,579
Maximum
Class Of Stock [Line Items]
Stock option period, expiration	10 years
Stock option period, vested	4 years
Minimum
Class Of Stock [Line Items]
Stock option period, expiration	7 years
Stock option period, vested	1 year
2012 Plan
Class Of Stock [Line Items]
Stock option shares outstanding	461,821
Number of equity awards available for grant	0
2002 Plan
Class Of Stock [Line Items]
Stock option shares outstanding	161,657
Number of equity awards available for grant	0
2014 Plan
Class Of Stock [Line Items]
Stock option shares outstanding	1,875,277
Number of equity awards available for grant	436,549
Terms of shares available for issuance	The number of shares available for issuance under the 2014 Plan also includes an annual increase on the first day of each fiscal year beginning in 2015, equal to the least of: 895,346 shares; 4% of the outstanding shares of common stock as of the last day of our immediately preceding fiscal year; or such other amount as our board of directors may determine.
Common stock capital shares reserved for future issuance maximum annual increase	895,346
Percentage on outstanding shares of common stock	4.00%
Number of additional number of shares reserve to provision	791,296
2012 Plan and 2002 Plan | Maximum
Class Of Stock [Line Items]
Stock option shares outstanding	2,328,569
2014 ESPP Plan
Class Of Stock [Line Items]
Number of equity awards available for grant	438,365
Terms of shares available for issuance	The number of shares available for issuance under the 2014 ESPP Plan also includes an annual increase on the first day of each fiscal year beginning in 2015, equal to least of: 179,069 shares;1.5% of the outstanding shares of our common stock on the last day of our immediately preceding fiscal year; or Such other amount as may be determined by the administrator
Percentage on outstanding shares of common stock	1.50%
Number of additional number of shares reserve to provision	179,069
Maximum percentage of common stock eligible to purchase through payroll deductions for participants	15.00%
Maximum number of shares available for participant to purchase during period	1,500
Potential increase of shares available for issuance	179,069
Purchase price as percentage of stock price on offering period	85.00%
Purchase price as percentage of stock price on exercise date	85.00%

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Options Activity (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Class Of Stock [Line Items]
Stock Options Outstanding, Beginning balance	2,295,370
Stock Options, Granted	672,998
Stock Options, Exercised	(424,462)
Stock Options, Forfeited	(44,636)
Stock Options, Expired	(515)
Stock Options Outstanding, Ending balance	2,498,755	2,295,370
Stock Options, Vested and exercisable	1,039,364
Stock Options, Vested and expected to vest	2,390,297
Price per share, Expired	$ 8.70
Outstanding, Weighted average exercise price, Beginning balance	19.36
Weighted average exercise price, Granted	44.47
Weighted average exercise price, Exercised	10.84
Weighted average exercise price, Forfeited	27.99
Weighted average exercise price, Expired	8.70
Outstanding, Weighted average exercise price, Ending balance	27.41	$ 19.36
Weighted average exercise price, Vested and exercisable	15.63
Weighted average exercise price, Vested and expected to vest	$ 27.18
Remaining weighted average contractual term, Outstanding	5 years 7 months 24 days	5 years 11 months 23 days
Remaining weighted average contractual term, Vested and exercisable	5 years 2 months 5 days
Remaining weighted average contractual term, Vested and expected to vest	5 years 7 months 17 days
Outstanding, Per share average intrinsic value	$ 32.49	$ 21.07
Per share average intrinsic value, Vested and exercisable	44.27
Per share average intrinsic value, Vested and expected to vest	32.72
Minimum
Class Of Stock [Line Items]
Outstanding, Price per share, Beginning balance	0.60
Price per share, Granted	44.19
Price per share, Exercised	0.60
Price per share, Forfeited	8.37
Outstanding, Price per share, Ending balance	0.60	0.60
Price per share, Vested and exercisable	0.60
Price per share, Vested and expected to vest	0.60
Maximum
Class Of Stock [Line Items]
Outstanding, Price per share, Beginning balance	46.66
Price per share, Granted	56.72
Price per share, Exercised	46.66
Price per share, Forfeited	44.19
Outstanding, Price per share, Ending balance	56.72	$ 46.66
Price per share, Vested and exercisable	56.72
Price per share, Vested and expected to vest	$ 56.72

Stockholders' Equity - Summar53

Stockholders' Equity - Summary of Stock-based Compensation Expense Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock-based compensation expense by type of award:
Stock-based compensation expense	$ 1,953	$ 1,016	$ 5,404	$ 2,343
Employee Stock Purchase Plan
Stock-based compensation expense by type of award:
Stock-based compensation expense	95	75	341	265
Stock options
Stock-based compensation expense by type of award:
Stock-based compensation expense	$ 1,858	$ 941	$ 5,063	$ 2,078

Stockholders' Equity - Summar54

Stockholders' Equity - Summary of Stock-based Compensation Expense Recognized in Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Class Of Stock [Line Items]
Stock-based compensation expense	$ 1,953	$ 1,016	$ 5,404	$ 2,343
Cost of Revenue
Class Of Stock [Line Items]
Stock-based compensation expense	175	128	454	294
Sales and Marketing
Class Of Stock [Line Items]
Stock-based compensation expense	318	297	859	677
General and Administrative
Class Of Stock [Line Items]
Stock-based compensation expense	1,237	459	3,530	1,068
Research and Development
Class Of Stock [Line Items]
Stock-based compensation expense	$ 223	$ 132	$ 561	$ 304

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands	Jul. 26, 2016	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Commitments And Contingencies [Line Items]
Rent expense		$ 263		$ 221	$ 766	$ 661
Outstanding purchase orders with its outside vendors and suppliers		40,200			40,200
Gain contingency of future services and licensing fees			$ 250
Amount received after finalizing the payment of settlement	$ 1,250
Accrual for litigation settlement fees with in accounts payable and accrued expense		980			980
Accounts Payable and Accrued Liabilities
Commitments And Contingencies [Line Items]
Deferred gain contingency, Remaining portion		178			$ 178
General and Administrative
Commitments And Contingencies [Line Items]
Gain from settlement		$ 72	$ 1,000
Offices and Certain Equipment
Commitments And Contingencies [Line Items]
Operating leases expiration date					Jan. 31, 2022

Commitments and Contingencies56

Commitments and Contingencies - Minimum Aggregate Payments Due under Non-Cancelable Leases (Details) $ in Thousands	Sep. 30, 2016USD ($)
Commitments And Contingencies Disclosure [Abstract]
Remaining 3 months of 2016	$ 291
2,017	1,169
2,018	1,157
2,019	1,155
2,020	755
Thereafter	270
Total minimum payments	$ 4,797

Commitments and Contingencies57

Commitments and Contingencies - Schedule of Changes in Aggregate Product Warranty Liabilities (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Product warranty liability at beginning of period	$ 1,973	$ 1,115
Accruals for warranties issued	2,367	1,871
Adjustments related to preexisting warranties (including changes in estimates)	318	510
Settlements made (in cash or in kind)	(1,261)	(1,523)
Product warranty liability at end of period	$ 3,397	$ 1,973

Foreign Currency Exchange Con58

Foreign Currency Exchange Contracts and Hedging - Additional Information (Details)	9 Months Ended
	Sep. 30, 2016USD ($)Contract
Derivatives Fair Value [Line Items]
Number of contract designated hedges | Contract	14
Number of contract non-designated hedges | Contract	4
Non-Designated Derivative Contracts
Derivatives Fair Value [Line Items]
Derivative contracts notional amounts	$ 736,000
Designated Derivative Contracts
Derivatives Fair Value [Line Items]
Derivative contracts notional amounts	2,839,000
Unrealized gain on derivative	$ 27,000
Minimum
Derivatives Fair Value [Line Items]
Derivative contracts expiration period	1 month
Maximum
Derivatives Fair Value [Line Items]
Derivative contracts expiration period	6 months