Fair Value Measurements - Textual (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock Issued During Period, Shares, New Issues	0	0	0
Fixed Payment [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Business Combination, Contingent Consideration, Liability	$ 4,810	$ 40,370
Contingent and fixed payments [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Business Combination, Contingent Consideration, Liability	229,564	347,104
Common Class A | Common Stock [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Stock Issued During Period, Value, New Issues	$ 10,458	$ 0	$ 0
Stock Issued During Period, Shares, New Issues	691,559