Acquisition - Narrative (Details)		3 Months Ended	6 Months Ended
	Jun. 15, 2021 USD ($)	Sep. 30, 2021 USD ($) item	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 16, 2022 USD ($) $ / shares	Jun. 15, 2022 $ / shares	Jul. 15, 2021 USD ($) $ / shares
Acquisition.
Decrease in warrant liability			$ (185,000)	$ (219,000)
Warrant exercise price (in dollars per share) | $ / shares					$ 0.6665	$ 6.00
Fair value portion of warrants					$ 1,700,000
Risk Free Rate
Acquisition.
Warrant fair value measurement inputs					3.32
Volatility
Acquisition.
Warrant fair value measurement inputs					64.8
Expected dividends
Acquisition.
Warrant fair value measurement inputs					0
Obalon Therapeutics Inc.
Acquisition.
Warrant liability	$ 2,000,000.0	$ 1,300,000
Decrease in warrant liability		$ 700,000
Number of holders exercised fundamental transaction option | item		1
Fair value portion of warrants							$ 900,000
Reclassification of warrants							$ 500,000
Obalon Therapeutics Inc. | Minimum
Acquisition.
Warrant exercise price (in dollars per share) | $ / shares							$ 13.20
Obalon Therapeutics Inc. | Maximum
Acquisition.
Warrant exercise price (in dollars per share) | $ / shares							$ 15.00
Obalon Therapeutics Inc. | Developed technology
Acquisition.
Useful life			15 years
Obalon Therapeutics Inc. | Discount rate | Developed technology
Acquisition.
Discount rate			0.220
Obalon Therapeutics Inc. | Risk Free Rate
Acquisition.
Warrant fair value measurement inputs							0.0044
Obalon Therapeutics Inc. | Volatility
Acquisition.
Warrant fair value measurement inputs							1.221
Obalon Therapeutics Inc. | Expected dividends
Acquisition.
Warrant fair value measurement inputs							0