Employee Benefits - Pension and Other Defined Contribution Retirement Plan Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Pension Plans [Member] | U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	$ 596	$ 698	$ 1,788	$ 2,094
Interest cost on projected benefit obligation	4,790	4,561	14,370	13,682
Expected return on plan assets	(7,740)	(9,246)	(23,219)	(27,738)
Net amortization and deferrals	1,549	1,793	4,647	5,379
Net periodic benefit income	(805)	(2,194)	(2,414)	(6,583)
Total expense	1,591	(255)	5,753	135
Pension Plans [Member] | Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	4,470	5,956	13,410	17,080
Interest cost on projected benefit obligation	4,338	4,066	13,014	11,825
Expected return on plan assets	(12,032)	(12,873)	(36,096)	(37,340)
Net amortization and deferrals	2,972	4,185	8,916	12,096
Net periodic benefit income	(252)	1,334	(756)	3,661
Total expense	1,392	2,804	4,145	8,044
Defined Contribution and Other Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	196	221	587	663
Interest cost on projected benefit obligation	654	588	1,962	1,764
Net amortization and deferrals	(1,189)	(1,046)	(3,567)	(3,138)
Net periodic benefit income	(339)	(237)	(1,018)	(711)
Defined Contribution and Other Retirement Plans [Member] | U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Defined contribution and other retirement plans	2,396	1,939	8,167	6,718
Defined Contribution and Other Retirement Plans [Member] | Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Defined contribution and other retirement plans	$ 1,644	$ 1,470	$ 4,901	$ 4,383