Debt - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	May 14, 2019	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Mar. 16, 2020	Mar. 11, 2020
Debt Instrument [Line Items]
Long-term debt outstanding		$ 50,000		$ 50,000
Loan Agreement
Debt Instrument [Line Items]
Interest bearing rate upon customary events	4.00%
Warrants expire term	10 years
Warrants exercisable shares of common stock	16,446
Aggregate repurchase price of warrants	$ 500
Adjustments to additional paid-in-capital, warrants issued				300
Fair value of warrant liabilities	$ 400
Interest expense		$ 1,200	$ 1,300	$ 2,500	$ 2,000
Term Loans
Debt Instrument [Line Items]
Debt instrument, additional borrowing capacity amount						$ 25,000	$ 25,000
Debt instrument, interest rate percentage		7.25%		7.25%
Debt instrument, description				Under the original Loan Agreement, the monthly payments consisted of interest-only through May 31, 2021. On March 11, 2020, the Company entered into the first amendment and on March 11, 2021, the Company entered into the second amendment (together the “Amendments”) to the Loan Agreement. Pursuant to the Amendments, the interest-only payment period was initially extended through July 31, 2021, and was further extended until December 31, 2021, after the Company received positive data from its Phase 3 clinical trial in H. pylori infection sufficient to file a New Drug Application (“NDA”) with the U.S. Food and Drug Administration (“FDA”). The interest-only payment period could be further extended until November 30, 2022, if the Company receives positive data from its Phase 3 clinical trial in erosive esophagitis for vonoprazan sufficient to file an NDA with the FDA
Debt instrument, maturity date	May 01, 2024
Debt instrument, final payment fee percentage	8.25%
Debt instrument, final payment fee		$ 4,100		$ 4,100
Debt issuance costs	$ 200
Long-term debt outstanding		50,000		50,000
Accrued interest		$ 300		$ 300
Term Loans | Maximum
Debt Instrument [Line Items]
Debt instrument, prepayment fee percentage of outstanding principal amount	2.00%
Term Loans | Prime Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.75%
Debt instrument, interest rate percentage		5.00%		5.00%