Collaborative Arrangements - Parion Sciences, Inc. (Details) - USD ($)	1 Months Ended	3 Months Ended								12 Months Ended
	Jun. 30, 2015	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative revenues		$ 29,061,000	$ 26,292,000	$ 27,286,000	$ 232,545,000	$ 937,000	$ 259,000	$ 675,000	$ 74,000	$ 315,184,000	$ 1,945,000	$ 8,053,000
(Benefit from) provision for income taxes		10,257,000	(125,903,000)	4,337,000	3,985,000	$ (7,453,000)	$ 503,000	$ 18,130,000	$ 5,485,000	(107,324,000)	16,665,000	30,381,000
Intangible asset impairment charge		$ 0	255,340,000	0	$ 0					255,340,000	0	0
Parion Sciences, Inc
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Up-front payment	$ 80,000,000									85,000,000		80,000,000
Milestone payments											5,000,000
Prior to marketing approval, time period of notice required to terminate (in days)	90 days
Subsequent to marketing approval, time period of notice required to terminate (in days)	180 days
Change of control prior to clinical trial, time period of notice required to terminate (in days)	30 days
Term of agreement following first commercial sale (in years)	10 years
Business combination, consideration VIE	$ 255,300,000
Business combination, acquisition of less than 100 percent, noncontrolling interest, fair value	164,300,000
Business combination, recognized identifiable assets acquired and liabilities assumed, deferred tax liabilities	91,000,000
Other liabilities / assets, net	10,500,000
Collaborative revenues			20,000,000	$ 20,000,000
(Benefit from) provision for income taxes			(126,200,000)
Intangible asset impairment charge			255,300,000
Business combination, contingent consideration arrangements, change in amount of contingent consideration, liability			(69,600,000)
Income tax expense (benefit), attributable to intangible asset impairment			(97,700,000)
Income tax expense (benefit), attributable to decrease in the fair value of contingent consideration liability			$ (28,500,000)
Deconsolidation, gain (loss), amount										(7,100,000)
Parion Sciences, Inc | Enac Inhibitors in Cf
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement development and regulatory potential milestone payments maximum	485,000,000
Collaborative arrangement regulatory potential milestone payments maximum	360,000,000
Parion Sciences, Inc | Enac Inhibitors in Non Cf
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement development and regulatory potential milestone payments maximum	370,000,000
Parion Sciences, Inc | Additional Enac Inhibitors
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement development and regulatory potential milestone payments maximum	$ 230,000,000
Variable Interest Entity, Primary Beneficiary
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
(Benefit from) provision for income taxes										(114,090,000)	16,743,000	29,731,000
Business combination, contingent consideration arrangements, change in amount of contingent consideration, liability										(62,560,000)	54,850,000	4,530,000
Variable Interest Entity, Primary Beneficiary | Parion Sciences, Inc
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative revenues										40,000,000
(Benefit from) provision for income taxes										14,800,000
Business combination, contingent consideration arrangements, change in amount of contingent consideration, liability										$ (63,460,000)	$ 64,800,000	$ 3,660,000