Collaborative Arrangements - Aggregate VIE Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	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	Dec. 31, 2014
Variable Interest Entity, Primary Beneficiary, Does Not Hold Majority Voting Interest, Disclosures [Abstract]
(Benefit from) provision for income taxes	$ 10,257	$ (125,903)	$ 4,337	$ 3,985	$ (7,453)	$ 503	$ 18,130	$ 5,485	$ (107,324)	$ 16,665	$ 30,381
Net loss (income) attributable to noncontrolling interest	(1,501)	188,315	$ (13,173)	$ (1,792)	5,186	$ 696	$ (28,374)	$ (5,529)	171,849	(28,021)	31,847
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net:
Restricted cash and cash equivalents (VIE)	1,489				47,762				1,489	47,762
Prepaid expenses and other current assets	165,635				71,253				165,635	71,253
Intangible assets	29,000				284,340				29,000	284,340
Other assets	7,783				11,885				7,783	11,885
Accounts payable	73,994				61,451				73,994	61,451
Other current liabilities	443,961				315,249				443,961	315,249
Deferred tax liability	6,341				134,063				6,341	134,063
Other liabilities	26,048				28,699				26,048	28,699
Noncontrolling interest	13,727				181,609				13,727	181,609
Parion Sciences, Inc
Variable Interest Entity, Primary Beneficiary, Does Not Hold Majority Voting Interest, Disclosures [Abstract]
(Benefit from) provision for income taxes		(126,200)
Decrease (increase) in fair value of contingent payments		$ 69,600
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity, Primary Beneficiary, Does Not Hold Majority Voting Interest, Disclosures [Abstract]
Loss attributable to noncontrolling interest before (benefit from) provision for income taxes and changes in fair value of contingent payments									223,379	10,086	6,646
(Benefit from) provision for income taxes									(114,090)	16,743	29,731
Decrease (increase) in fair value of contingent payments									62,560	(54,850)	(4,530)
Net loss (income) attributable to noncontrolling interest									171,849	(28,021)	31,847
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net:
Restricted cash and cash equivalents (VIE)	1,489				47,762				1,489	47,762
Prepaid expenses and other current assets	22				6,812				22	6,812
Intangible assets	29,000				284,340				29,000	284,340
Other assets	256				399				256	399
Accounts payable	1,021				415				1,021	415
Taxes payable	2,171				1,330				2,171	1,330
Other current liabilities	0				2,137				0	2,137
Deferred tax liability	4,756				131,446				4,756	131,446
Other liabilities	0				300				0	300
Noncontrolling interest	13,727				181,609				13,727	181,609
Variable Interest Entity, Primary Beneficiary | Parion Sciences, Inc
Variable Interest Entity, Primary Beneficiary, Does Not Hold Majority Voting Interest, Disclosures [Abstract]
(Benefit from) provision for income taxes									14,800
Decrease (increase) in fair value of contingent payments									63,460	(64,800)	(3,660)
Contingent consideration liability	0				238,800				0	238,800
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net:
Intangible assets											255,300
Variable Interest Entity, Primary Beneficiary | BioAxone Biosciences, Inc
Variable Interest Entity, Primary Beneficiary, Does Not Hold Majority Voting Interest, Disclosures [Abstract]
Decrease (increase) in fair value of contingent payments									(900)	9,950	$ (870)
Contingent consideration liability	$ 18,900				$ 18,000				$ 18,900	$ 18,000
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net:
Intangible assets												$ 29,000