Fair Value of Financial Assets and Liabilities - Changes in Level 3 Contingent Consideration Measured at Fair Value on Recurring Basis (Detail) - Accounts Payable Accrued and Other Liabilities [Member] - Contingent Consideration [Member] - Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Opening Balance	$ 55,614	$ 65,043
Total realized and unrealized gains (losses) included in Net income(loss)	(1,042)	4
Unrealized gains (losses) included in Other comprehensive income (loss)	(44)	(5)
Issuances	6,190	833
Settlements	(10,153)	(1,540)
Closing Balance	52,737	64,337
Unrealized gains (losses) for Level 3 Assets / Liabilities Outstanding	$ (1,087)	$ 1