Debt - Convertible Subordinated Notes (Details)				1 Months Ended		3 Months Ended			9 Months Ended
	Apr. 18, 2022 USD ($)	Mar. 07, 2022 USD ($)	Jul. 31, 2014 $ / shares $ / Item	Jul. 31, 2014 $ / shares $ / Item shares	Jan. 31, 2013 USD ($) Item $ / shares $ / Item shares	Sep. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2016 USD ($)
Debt
Payment for repurchase of debt instrument									$ 165,131,000	$ 0
Accrued interest payable						$ 5,702,000			5,702,000		$ 4,152,000
Loss on extinguishment of debt						0		$ 0	(20,662,000)	0
Principal						549,704,000			549,704,000		433,484,000
Debt discount and issuance costs, net						(9,894,000)			$ (9,894,000)		(38,831,000)
2023 Notes | Privately-negotiated capped call option
Debt
Cap price for the underlying number of shares (in dollars per share) | $ / Item			27.04	27.04
2023 Notes | Convertible subordinated notes
Debt
Loan amount					$ 287,500,000
Debt instrument maturity date					Jan. 15, 2023
Proceeds from issuance of notes payable, net of debt issuance costs					$ 281,200,000
Debt Instrument, annual interest rate					2.125%
Initial conversion, shares per $1,000 principal amount | shares | shares					35.9903
Adjusted conversion, shares per $1,000 principal amount | shares				50.5818
Conversion price of convertible notes into common stock (in dollars per share) | $ / shares					$ 27.79
Ratio of repurchase price to the principal amount									100.00%
Portion of debt retired, face value		$ 144,800,000					$ 144,800,000					$ 14,100,000
Portion of debt retired, carrying value		144,500,000										$ 13,900,000
Payment for repurchase of debt instrument		$ 165,600,000					$ 165,600,000
Percentage of notes repurchased		60.00%
Accrued interest payable		$ 400,000
Unamortized debt issuance cost		300,000
Loss on extinguishment of debt		20,700,000
Principal	$ 96,200,000	96,200,000				96,204,000			$ 96,204,000		240,984,000
Debt discount and issuance costs, net		$ 200,000				(73,000)			(73,000)		(620,000)
Net Carrying Amount						96,131,000			96,131,000		$ 240,364,000
Interest expense
Contractual interest expense						511,000		1,280,000	2,106,000	3,840,000
Amortization of debt issuance costs						59,000		143,000	240,000	431,000
Total interest and amortization expense						$ 570,000		$ 1,423,000	$ 2,346,000	$ 4,271,000
2023 Notes | Convertible subordinated notes | Privately-negotiated capped call option
Debt
Payments for capped call options					$ 36,800,000
Number of derivative instruments purchased | Item					2
Capped call strike price | $ / shares			$ 19.77	$ 19.77
Strike price for the underlying number of shares (in dollars per share) | $ / shares			$ 27.79	$ 19.77	$ 27.79
Cap price for the underlying number of shares (in dollars per share) | $ / Item			38.00	38.00	38.00
2023 Notes | Convertible subordinated notes | Stock prices above $38.00 per share | Maximum
Debt
Net shares settlement payable to the entity | shares					2,779,659
2023 Notes | Convertible subordinated notes | Stock prices below $27.79 per share | Minimum
Debt
Net shares settlement payable to the entity | shares					0
2023 Notes | Old Rate [Member] | Convertible subordinated notes
Debt
Effective interest rate		2.36%
2023 Notes | New Rate [Member] | Convertible subordinated notes
Debt
Effective interest rate		2.37%
Innoviva's Common Stock | 2023 Notes | Convertible subordinated notes
Debt
Notes converted into common stock, Amount	$ 3,000.0