Employee Benefit Plans - Summary of Changes in Benefit Obligations, Fair Value of Assets, Funded Status and Amounts Recognized in Consolidated Statements of Financial Condition (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Change in benefit obligation
Benefit obligation at beginning of year	$ 764,169
Benefit obligation at end of year	694,187	$ 764,169
Change in plan assets
Fair value of plan assets at beginning of year	672,576
Fair value of plan assets at end of year	656,084	672,576
Pension Plans [Member]
Change in benefit obligation
Benefit obligation at beginning of year	764,169	709,850
Service cost	1,530	971	$ 940
Interest cost	24,600	30,041	27,219
Actuarial (gain) loss	(22,395)	97,495
Benefits paid	(33,253)	(29,663)
Foreign currency translation and other adjustments	(40,464)	(44,525)
Benefit obligation at end of year	694,187	764,169	709,850
Change in plan assets
Fair value of plan assets at beginning of year	672,576	643,844
Actual return on plan assets	9,873	91,829	41,353
Employer contributions	39,301	7,648	2,274
Benefits paid	(32,321)	(28,877)	(23,258)
Foreign currency translation and other adjustments	(33,345)	(41,868)
Fair value of plan assets at end of year	656,084	672,576	643,844
Funded (deficit) at end of year	(38,103)	(91,593)
Prepaid pension asset (included in "other assets")	20,785
Accrued benefit liability (included in "other liabilities")	(58,888)	(91,593)
Net amount recognized	(38,103)	(91,593)
Actuarial net loss (gain)	165,462	186,637
Prior service cost	2,362	5,235
Net amount recognized	167,824	191,872
Medical Plan [Member]
Change in benefit obligation
Benefit obligation at beginning of year	5,514	5,080
Service cost	27	33	53
Interest cost	179	194	182
Actuarial (gain) loss	(694)	428
Benefits paid	(276)	(221)
Benefit obligation at end of year	4,750	5,514	5,080
Change in plan assets
Employer contributions	276	221	176
Benefits paid	(276)	(221)	$ (176)
Funded (deficit) at end of year	(4,750)	(5,514)
Accrued benefit liability (included in "other liabilities")	(4,750)	(5,514)
Net amount recognized	(4,750)	(5,514)
Actuarial net loss (gain)	(335)	360
Net amount recognized	$ (335)	$ 360