Derivatives - Fair Values of Derivatives Reported on Consolidated Statements of Financial Condition (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 1,993	$ 1,048
Derivative Liabilities	182,223	195,689
Forward Foreign Currency Exchange Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	1,993	1,015
Derivative Liabilities	2,792	1,584
Total Return Swaps and Other [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	0	33
Derivative Liabilities	9,043	531
LFI and Other Similar Deferred Compensation Arrangements [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ 170,388	$ 193,574