Collaborative Arrangements and Acquisitions - Aggregate VIE Financial Information, Items Related to the Company's VIEs (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted cash and cash equivalents (VIE)	$ 64,628	$ 47,762
Prepaid expenses and other current assets	107,082	70,534
Intangible assets	284,340	284,340
Goodwill	50,384	50,384
Other assets	9,943	11,885
Accounts payable	75,941	61,451
Accrued expenses	345,062	315,249
Other liabilities, current portion	24,770	10,943
Deferred tax liability	136,649	134,063
Other liabilities, excluding current portion	25,221	28,699
Noncontrolling interest	195,958	181,609
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Restricted cash and cash equivalents (VIE)	64,628	47,762
Prepaid expenses and other current assets	1,198	6,812
Intangible assets	284,340	284,340
Goodwill	19,391	19,391
Other assets	752	399
Accounts payable	702	415
Accrued expenses	4,118	1,330
Other liabilities, current portion	1,610	2,137
Deferred tax liability	134,305	131,446
Other liabilities, excluding current portion	300	300
Noncontrolling interest	$ 195,958	$ 181,609