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, 2016	Mar. 31, 2015
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Opening Balance	$ 65,043	$ 56,299
Total realized and unrealized gains (losses) included in Net income	4	(1,236)
Unrealized gains (losses) included in Other comprehensive income (loss)	(5)	41
Issuances	833	7,564
Settlements	(1,540)	(1,544)
Closing Balance	64,337	63,514
Unrealized gains (losses) for Level 3 Assets / Liabilities Outstanding	$ 1	$ 1,195