Fair Value Measurements - Schedule of Changes to Deferred Acquisition Consideration (Details) - USD ($)		3 Months Ended		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Business Combination, Contingent Consideration, Liability		$ 347,104,000	$ 205,368,000	$ 347,104,000	$ 205,368,000
Payments Related To Acquisition				134,056,000	78,322,000	$ 119,572,000
Contingent Payment [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability		41,910	1,751	36,344,000	16,467,000	35,914,000
Contingent Payment [Member] | Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Business Combination, Contingent Consideration, Liability		$ 306,734,000	$ 172,227,000	306,734,000	172,227,000	$ 151,848,000
Payments Related To Acquisition				77,301,000	61,441,000
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Business Combination, Consideration Transferred, Liabilities Incurred	[1]			174,530,000	68,642,000
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	[2]			41,636,000	20,816,000
Transfers (to) from fixed payments				0	(5,146,000)
Liabilities, Fair Value Adjustment				$ (4,358,000)	$ (2,492,000)

[1] .

[2] .