Organization and Basis of Presentation	3 Months Ended
Mar. 31, 2020
Accounting Policies [Abstract]
Organization and Basis of Presentation	Organization and Basis of Presentation Obalon Therapeutics, Inc., or the Company, was incorporated in the state of Delaware on January 2, 2008. The Company is a vertically-integrated medical device company focused on developing and commercializing innovative medical devices to treat obesity. Using its patented technology, the Company has developed the Obalon® balloon system, the first and only U.S. Food and Drug Administration, or FDA, approved swallowable, gas-filled intragastric balloon designed to provide progressive and sustained weight loss in obese patients. The unaudited interim condensed consolidated financial statements include the accounts of Obalon Therapeutics, Inc., and its wholly owned subsidiary, Obalon Center for Weight Loss, Inc. The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, and include the Company's accounts and accounts of its wholly-owned subsidiary. The Company also consolidates variable interest entities or VIE for which it is the primary beneficiary. The primary beneficiary has both (a) the power to direct the activities of the VIE that most significantly affect the entity’s economic performance and (b) either the obligation to absorb losses or the right to receive benefits. Refer to Note 10, “Variable Interest Entity” for further details. All intercompany transactions and balances have been eliminated in consolidation. The Company’s principal operations are located in Carlsbad, California, and it operates in one business segment. Reverse Stock Split On July 24, 2019, the Company filed a certificate of amendment to its certificate of incorporation with the Secretary of State of the State of Delaware to effect a one-for-ten reverse split of its issued and outstanding common stock. The accompanying consolidated financial statements and notes thereto give retrospective effect to the reverse stock split for all periods presented. All issued and outstanding common stock, options exercisable for common stock, restricted stock units, performance restricted stock units, and per share amounts contained in the consolidated financial statements have been retrospectively adjusted to reflect this reverse stock split for all periods presented. The number of authorized shares of common stock was not changed by virtue of the reverse stock split and remained at 100.0 million shares. Liquidity As of March 31, 2020, the Company has devoted a substantial portion of its efforts to product development, raising capital, and building infrastructure, and, since January 2017, U.S. commercialization. The Company has incurred operating losses and has experienced negative cash flows from operations since its inception. In July 2012, the Company realized initial revenue from its planned principal operations. The Company recognized total revenue of $0.8 million and $1.8 million for the three months ended March 31, 2020 and 2019, respectively. However, the Company has not yet established an ongoing source of revenue sufficient to cover its operating costs and has funded its activities to date almost exclusively from debt and equity financings. As reflected in the accompanying condensed consolidated financial statements, the Company has a limited operating history and the sales and income potential of the Company’s business are unproven. The Company has not been profitable since inception, and as of March 31, 2020, its accumulated deficit was $177.7 million. Since inception, the Company has financed its operations primarily through private placements of its preferred stock, the sale of common stock in its IPO and in subsequent public offerings and private placements, and, to a lesser extent, debt financing arrangements. As of March 31, 2020, the Company had cash and cash equivalents of $8.9 million. The Company expects to continue to incur net losses for the foreseeable future. The Company is subject to risks and uncertainties as a result of the COVID-19 pandemic. In late 2019, a novel strain of coronavirus, COVID-19, was reported to have surfaced in Wuhan, China. Since then, COVID-19 has spread globally. To date, COVID-19 has had, and will continue to have, an adverse impact on the Company’s operations and expenses as a result of the preventive and precautionary measures that the Company, its customers, other businesses, and governments are taking, including the deferral of elective medical procedures and diversion of capital and other resources. In March 2020, the Company suspended all new patient treatments at its Obalon-branded retail centers due to the ongoing COVID-19 pandemic. The Company is taking further steps to significantly reduce expenses in an effort to extend its cash runway while it evaluates potential business options and strategic alternatives that may be available when and if the current COVID-19 crisis stabilizes and the economy rebounds. The Company has significantly reduced the organization to only essential personnel and expects that, after a transition, only two full-time employees will remain. All Obalon-branded retail centers have been shutdown with no intention to reopen, and the Company has halted plans for future expansion. The Company does not expect to restart shipments to U.S. customers and has terminated the agreement with its international distributor, Al Danah Medical Company W.L.L. As the Company reduces its personnel to two full time employees, it will continue to seek strategic alternatives in the best interest of stockholders, while it pursues third-party payor reimbursement and coverage for the Obalon Balloon System. The decision to shift the Company's strategy to focus on pursuing reimbursement occurred after the end of the first quarter of 2020. If the Company is unsuccessful in those two endeavors over the next several months, it may be forced to liquidate the business. As a result of the above factors, there is substantial doubt about the Company's ability to continue as a going concern for the twelve months following the issuance date of the unaudited interim condensed consolidated financial statements for the three months ended March 31, 2020.

Organization and Basis of Presentation

Obalon Therapeutics, Inc., or the Company, was incorporated in the state of Delaware on January 2, 2008. The Company is a vertically-integrated medical device company focused on developing and commercializing innovative medical devices to treat obesity. Using its patented technology, the Company has developed the Obalon® balloon system, the first and only U.S. Food and Drug Administration, or FDA, approved swallowable, gas-filled intragastric balloon designed to provide progressive and sustained weight loss in obese patients.

The unaudited interim condensed consolidated financial statements include the accounts of Obalon Therapeutics, Inc., and its wholly owned subsidiary, Obalon Center for Weight Loss, Inc.

The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, and include the Company's accounts and accounts of its wholly-owned subsidiary. The Company also consolidates variable interest entities or VIE for which it is the primary beneficiary. The primary beneficiary has both (a) the power to direct the activities of the VIE that most significantly affect the entity’s economic performance and (b) either the obligation to absorb losses or the right to receive benefits. Refer to Note 10, “Variable Interest Entity” for further details. All intercompany transactions and balances have been eliminated in consolidation.

The Company’s principal operations are located in Carlsbad, California, and it operates in one business segment.

Reverse Stock Split

On July 24, 2019, the Company filed a certificate of amendment to its certificate of incorporation with the Secretary of State of the State of Delaware to effect a one-for-ten reverse split of its issued and outstanding common stock. The accompanying consolidated financial statements and notes thereto give retrospective effect to the reverse stock split for all periods presented. All issued and outstanding common stock, options exercisable for common stock, restricted stock units, performance restricted stock units, and per share amounts contained in the consolidated financial statements have been retrospectively adjusted to reflect this reverse stock split for all periods presented. The number of authorized shares of common stock was not changed by virtue of the reverse stock split and remained at 100.0 million shares.

Liquidity

As of March 31, 2020, the Company has devoted a substantial portion of its efforts to product development, raising capital, and building infrastructure, and, since January 2017, U.S. commercialization. The Company has incurred operating losses and has experienced negative cash flows from operations since its inception. In July 2012, the Company realized initial revenue from its planned principal operations. The Company recognized total revenue of $0.8 million and $1.8 million for the three months ended March 31, 2020 and 2019, respectively. However, the Company has not yet established an ongoing source of revenue sufficient to cover its operating costs and has funded its activities to date almost exclusively from debt and equity financings.

As reflected in the accompanying condensed consolidated financial statements, the Company has a limited operating history and the sales and income potential of the Company’s business are unproven. The Company has not been profitable since inception, and as of March 31, 2020, its accumulated deficit was $177.7 million. Since inception, the Company has financed its operations primarily through private placements of its preferred stock, the sale of common stock in its IPO and in subsequent public offerings and private placements, and, to a lesser extent, debt financing arrangements. As of March 31, 2020, the Company had cash and cash equivalents of $8.9 million. The Company expects to continue to incur net losses for the foreseeable future.

The Company is subject to risks and uncertainties as a result of the COVID-19 pandemic. In late 2019, a novel strain of coronavirus, COVID-19, was reported to have surfaced in Wuhan, China. Since then, COVID-19 has spread globally. To date, COVID-19 has had, and will continue to have, an adverse impact on the Company’s operations and expenses as a result of the preventive and precautionary measures that the Company, its customers, other businesses, and governments are taking, including the deferral of elective medical procedures and diversion of capital and other resources. In March 2020, the Company suspended all new patient treatments at its Obalon-branded retail centers due to the ongoing COVID-19 pandemic. The Company is taking further steps to significantly reduce expenses in an effort to extend its cash runway while it evaluates potential business options and strategic alternatives that may be available when and if the current COVID-19 crisis stabilizes and the economy rebounds. The Company has significantly reduced the organization to only essential personnel and expects that, after a transition, only two full-time employees will remain. All Obalon-branded retail centers have been shutdown with no intention to reopen, and the Company has halted plans for future expansion. The Company does not expect to restart shipments to U.S. customers and has terminated the agreement with its international distributor, Al Danah Medical Company W.L.L. As the Company reduces its personnel to two full time employees, it will continue to seek strategic alternatives in the best interest of stockholders, while it pursues third-party payor reimbursement and coverage for the Obalon Balloon System. The decision to shift the Company's strategy to focus on pursuing reimbursement occurred after the end of the first quarter of 2020. If the Company is unsuccessful in those two endeavors over the next several months, it may be forced to liquidate the business. As a result of the above factors, there is substantial doubt about the Company's ability to continue as a going concern for the twelve months following the issuance date of the unaudited interim condensed consolidated financial statements for the three months ended March 31, 2020.