Basis of Presentation and Summary of Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2020
Accounting Policies [Abstract]
Basis of Consolidation	Basis of consolidation The consolidated financial statements include the accounts of Inogen, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated.
Use of Estimates	Use of estimates The preparation of consolidated 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 consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. 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 and determining the stand-alone selling price (SSP) of performance obligations, inventory and rental asset valuations and write-downs, accounts receivable allowances for bad debts, returns and adjustments, warranty expense, stock compensation expense, depreciation and amortization, income tax provision and uncertain tax positions, fair value of financial instruments, fair value of acquired intangible assets and goodwill and fair value of earnout liabilities. Actual results could differ from these estimates.
Government Grants	The Company may receive cash payments from government grants during a public health emergency (PHE). The Company considers the nature and substance of the government grant and records the cash payment in accordance with the terms and conditions of the grant. Income is deferred until all considerations required for receiving the grant are met and is recognized in the consolidated statements of comprehensive income based on the nature of the terms and conditions of the grant. In the three months ended June 30, 2020, the Company received a grant of $6,200 from the Public Health and Social Services Emergency Fund (Relief Fund), which was among the provisions of the Coronavirus Aid, Relief, and Economic Security Act (CARES) Act signed into law on March 27, 2020. During the three months ended June 30, 2020, the Company recorded $5,600 in other income, which was associated with lost revenues from the COVID-19 PHE, and a $600 benefit in general and administrative expense due to COVID-19 PHE related costs incurred in the quarter.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently issued accounting pronouncements not yet adopted In December 2019, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The new guidance simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The new guidance also improves consistent application of and simplifies U.S. GAAP for other areas of Topic 740 by clarifying and amending the existing guidance. The ASU is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. The Company is currently evaluating the effect of the new guidance.
Recently Adopted Accounting Pronouncements	Recently adopted accounting pronouncements In June 2016, the FASB issued ASU No. 2016-13, Accounting for Credit Losses (Topic 326). The new standard requires the use of an “expected loss” model on certain types of financial instruments. The standard also amends the impairment model for available-for-sale debt securities and requires estimated credit losses to be recorded as allowances instead of reductions to amortized cost of the securities. The Company adopted this standard on January 1, 2020, and adoption of this standard did not have a material impact on the Company’s consolidated financial statement presentation or results. In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment. The new guidance eliminates step two of the goodwill impairment test. Under the new guidance, an entity should recognize an impairment charge for the amount by which a reporting unit’s carrying value exceeds its fair value. The Company adopted this standard on January 1, 2020, and adoption of this standard did not have a material impact on the Company’s consolidated financial statement presentation or results. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement. The new guidance modifies the disclosure requirements on fair value measurements. The Company adopted this standard on January 1, 2020, and adoption of this standard did not have a material impact on the Company’s consolidated financial statement presentation or results.
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. Management reports financial information on a consolidated basis to the Company’s chief operating decision maker.

Use of estimates

The preparation of consolidated 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 consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. 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 and determining the stand-alone selling price (SSP) of performance obligations, inventory and rental asset valuations and write-downs, accounts receivable allowances for bad debts, returns and adjustments, warranty expense, stock compensation expense, depreciation and amortization, income tax provision and uncertain tax positions, fair value of financial instruments, fair value of acquired intangible assets and goodwill and fair value of earnout liabilities. Actual results could differ from these estimates.

Recently Issued Accounting Pronouncements Not Yet Adopted

Recently issued accounting pronouncements not yet adopted

In December 2019, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The new guidance simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The new guidance also improves consistent application of and simplifies U.S. GAAP for other areas of Topic 740 by clarifying and amending the existing guidance. The ASU is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. The Company is currently evaluating the effect of the new guidance.

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. Management reports financial information on a consolidated basis to the Company’s chief operating decision maker.