Share-Based Compensation (Details) $ / shares in Units, $ in Thousands				1 Months Ended	12 Months Ended
	Sep. 25, 2015 USD ($) $ / shares shares	Aug. 28, 2015	Jun. 02, 2014 plan shares	Aug. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) item $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2011 shares	Mar. 31, 2016 shares	Jun. 30, 2015 USD ($)	Oct. 31, 2014 shares
Share-Based Compensation
Number of plans | plan			2
Transferred from parent					$ 0	$ 0	$ 17,043
Share-based compensation expense					41,169	54,050	43,234
Common Stock Stock Dividend Ratio			0.286
Unrecognized compensation cost					74,107
Research and development
Share-Based Compensation
Share-based compensation expense				$ 16,700	20,202	25,770	21,191
Selling, general and administrative
Share-Based Compensation
Share-based compensation expense					$ 20,967	28,280	22,043
Senior management
Share-Based Compensation
Vesting period					5 years
Options
Share-Based Compensation
Share-based compensation expense					$ 7,591	14,063	9,404
Unrecognized compensation cost					$ 14,596
Weighted-average amortization period - years					2 years 6 months
RSUs
Share-Based Compensation
Share-based compensation expense					$ 20,946	$ 10,471	0
RSUs issued (in shares) | shares					2,344,034	3,399,924
Unrecognized compensation cost					$ 48,731
Weighted-average amortization period - years					2 years 10 months 24 days
RSU and RSA activity ( including Performance RSUs and RSAs)
Outstanding at beginning of year | shares					2,988,041
Granted (in shares) | shares					2,344,034	3,399,924
Released (in shares) | shares					(1,185,905)
Forfeited (in shares) | shares					(537,052)	(411,883)
Outstanding at end of year | shares					3,609,118	2,988,041
Additional disclosures
Aggregate intrinsic value outstanding					$ 115,100	$ 49,000
Total estimated fair value of RSUs vested					21,400	$ 1,600
RSAs
Additional disclosures
Aggregate intrinsic value outstanding					$ 45,900
Performance-Contingent Awards - RSUs | Senior management
Share-Based Compensation
Shares approved for grant (in shares) | shares									135,000
Performance-Contingent Awards - RSAs
Share-Based Compensation
RSUs issued (in shares) | shares					1,575,000	0
RSU and RSA activity ( including Performance RSUs and RSAs)
Outstanding at beginning of year | shares					0
Granted (in shares) | shares					1,575,000	0
Released (in shares) | shares					0
Forfeited (in shares) | shares					(135,000)	0
Outstanding at end of year | shares					1,440,000	0
Performance-Contingent Awards - RSAs | Senior management
Share-Based Compensation
Shares approved for grant (in shares) | shares									1,575,000
Performance-Contingent Awards - RSAs and RSUs
Share-Based Compensation
Share-based compensation expense					$ 1,808	$ 0	0
Unrecognized compensation cost					$ 4,865
Weighted-average amortization period - years					3 years 6 months
ESPP
Share-Based Compensation
Share-based compensation expense					$ 1,702	2,269	954
Unrecognized compensation cost					$ 1,102
Weighted-average amortization period - years					1 year
Innoviva | Options
Share-Based Compensation
Share-based compensation expense					$ 3,973	5,199	4,378
Unrecognized compensation cost					$ 3,310
Weighted-average amortization period - years					1 year 1 month 6 days
Innoviva | RSUs
Share-Based Compensation
Share-based compensation expense					$ 1,547	3,292	3,169
Unrecognized compensation cost					$ 215
Weighted-average amortization period - years					2 months 12 days
Innoviva | RSAs
Share-Based Compensation
Share-based compensation expense					$ 2,597	7,590	3,796
Unrecognized compensation cost					$ 1,287
Weighted-average amortization period - years					1 year 6 months
Innoviva | RSAs | Performance-Contingent
Share-Based Compensation
Period for which compensation committee has approved grants					3 years
Share-based compensation expense					$ 1,005	$ 11,166	$ 4,490
Unrecognized compensation cost					$ 1
Weighted-average amortization period - years					1 month 6 days
2013 EIP and 2014 NEEIP
Number of Shares Subject To Outstanding Options
Balance at the beginning of period | shares					2,311,164	3,962,426	0
Granted ( in shares) | shares					474,675	750,775	4,235,059
Exercised (in shares) | shares					197,328
Forfeited (in shares) | shares					(357,716)	(2,402,037)	(272,633)
Balance at the end of period | shares					2,230,795	2,311,164	3,962,426
Weighted-Average Exercise Price of Outstanding Options
Balance at the beginning of the period (in dollars per share) | $ / shares					$ 23.07	$ 24.73	$ 0.00
Granted (in dollars per share) | $ / shares					24.06	14.26	24.75
Exercised (in dollars per share) | $ / shares					22.18
Forfeited (in dollars per share) | $ / shares					19.83	23.05	25.01
Balance at the end of the period (in dollars per share) | $ / shares					$ 23.88	$ 23.07	$ 24.73
Additional disclosures
Aggregate intrinsic value of options outstanding					$ 18,100	$ 1,400
Aggregate intrinsic value of options exercisable					7,600
Total estimated fair value of options vested					$ 7,700	$ 10,700
2013 EIP and 2014 NEEIP | Options
Weighted-average assumptions
Risk-free interest rate, minimum (as a percent)					1.10%	1.40%	1.70%
Risk-free interest rate, maximum (as a percent)					1.90%	1.90%	2.00%
Expected term (in years)					6 years	6 years
Expected volatility, minimum (as a percent)					53.00%	71.00%	64.00%
Expected volatility, maximum (as a percent)					73.00%	78.00%	70.00%
Dividend yield (as a percent)					0.00%	0.00%	0.00%
Weighted-average estimated fair value (in dollars per share) | $ / shares					$ 13.28	$ 9.16	$ 15.55
2013 EIP and 2014 NEEIP | Minimum | Options
Weighted-average assumptions
Expected term (in years)							5 years
2013 EIP and 2014 NEEIP | Maximum | Options
Weighted-average assumptions
Expected term (in years)							6 years
2013 Equity Incentive Plan
Share-Based Compensation
Shares approved for grant (in shares) | shares			5,428,571
Percentage of total number of ordinary shares outstanding, used for automatic increase in shares to be issued					5.00%
Automatic increase in number of shares that may be issued | shares					3,428,571
2013 Equity Incentive Plan | Options
Share-Based Compensation
Maximum term for stock options					10 years
Vesting period					4 years
Percentage of stock options to be vested at end of year one					25.00%
Percentage of stock options to be vested monthly over remaining three years					75.00%
Period of forfeiture of unvested option upon termination of service					3 months
2014 New Employee Equity Incentive Plan
Share-Based Compensation
Shares approved for grant (in shares) | shares											750,000
2014 New Employee Equity Incentive Plan | Options
Share-Based Compensation
Maximum term for stock options					10 years
Vesting period					4 years
Percentage of stock options to be vested at end of year one					25.00%
Percentage of stock options to be vested monthly over remaining three years					75.00%
Period of forfeiture of unvested option upon termination of service					3 months
2013 Employee Share Purchase Plan
Share-Based Compensation
Shares approved for grant (in shares) | shares			857,142
Percentage of total number of ordinary shares outstanding, used for automatic increase in shares to be issued					1.00%
Automatic increase in number of shares that may be issued | shares					571,428
Purchase price as a percentage of fair market value of stock					85.00%
Consecutive and overlapping offering periods					24 months
Number of offering periods | item					4
Duration of purchase period					6 months
Maximum contributions as a percentage of employee's eligible compensation					15.00%
Weighted-average assumptions
Risk-free interest rate, minimum (as a percent)					0.40%	0.10%	0.10%
Risk-free interest rate, maximum (as a percent)					1.00%	0.90%	0.70%
Expected volatility, minimum (as a percent)					54.00%	46.00%	58.00%
Expected volatility, maximum (as a percent)					65.00%	62.00%	66.00%
Dividend yield (as a percent)					0.00%	0.00%	0.00%
Weighted-average estimated fair value (in dollars per share) | $ / shares					$ 9.63	$ 5.91	$ 10.95
2013 Employee Share Purchase Plan | Minimum
Weighted-average assumptions
Expected term (in years)					6 months	6 months	7 months 6 days
2013 Employee Share Purchase Plan | Maximum
Weighted-average assumptions
Expected term (in years)					2 years	2 years	2 years 2 months 12 days
2012 Equity Incentive Plan | Innoviva
Share-Based Compensation
Number of plans | plan			1
2012 Equity Incentive Plan | Innoviva | Options
Share-Based Compensation
Maximum term for stock options					10 years
Vesting period					4 years
Percentage of stock options to be vested at end of year one					25.00%
Percentage of stock options to be vested monthly over remaining three years					75.00%
Period of forfeiture of unvested option upon termination of service					3 months
Weighted-average assumptions
Risk-free interest rate, minimum (as a percent)							1.60%
Risk-free interest rate, maximum (as a percent)							2.10%
Expected volatility, minimum (as a percent)							52.00%
Expected volatility, maximum (as a percent)							61.00%
Dividend yield (as a percent)							0.00%
Weighted-average estimated fair value (in dollars per share) | $ / shares							$ 16.14
2012 Equity Incentive Plan | Innoviva | Minimum | Options
Weighted-average assumptions
Expected term (in years)							5 years
2012 Equity Incentive Plan | Innoviva | Maximum | Options
Weighted-average assumptions
Expected term (in years)							6 years
Employee Stock Option Exchange Program
Share-Based Compensation
Total incremental stock-based compensation expense recognized	$ 1,400
Vesting period	3 years
Share-based compensation expense					$ 500	$ 100
Employee Stock Option Exchange Program | Options
Share-Based Compensation
Options exchanged (in shares) | shares	1,975,009
Employee Stock Option Exchange Program | RSUs
Share-Based Compensation
Exchange ratio		2
RSUs issued (in shares) | shares	987,496
Fair value (USD per share) | $ / shares	$ 12.43
RSU and RSA activity ( including Performance RSUs and RSAs)
Granted (in shares) | shares	987,496
Employee Stock Option Exchange Program | Minimum | RSUs
Share-Based Compensation
Vesting period		3 years
Employee Stock Option Exchange Program | Maximum | RSUs
Share-Based Compensation
Vesting period		4 years
Special Long-Term Retention and Incentive Program | Innoviva | RSAs | Performance-Contingent
Share-Based Compensation
Shares approved for grant (in shares) | shares								1,290,000
Timeframe for achievement of performance conditions								6 years
Share-based compensation expense							$ 7,000
Special Long-Term Retention and Incentive Program | Innoviva | RSAs | Performance and Spin Off-Contingent
Share-Based Compensation
Share-based compensation expense					1,000	$ 7,100
Stock-based compensation expenses that will be recognized subject to sufficient performance conditions					9,500
Share based compensation expense recognized due to modification										$ 6,900
Potential planned | Selling, general and administrative
Share-Based Compensation
Share-based compensation expense				22,200
Potential planned | Maximum
Share-Based Compensation
Share-based compensation expense				$ 38,900
First tranche
Share-Based Compensation
Share-based compensation expense					1,800
Second and third tranches
Share-Based Compensation
Share-based compensation expense					$ 0