Employee Benefits - Pension and Other Defined Contribution Retirement Plan Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Pension Plans [Member] | U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	$ 596	$ 698
Interest cost on projected benefit obligation	4,790	4,560
Expected return on plan assets	(7,739)	(9,246)
Net amortization and deferrals	1,549	1,793
Net periodic benefit income	(804)	(2,195)
Total expense	1,886	60
Pension Plans [Member] | Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	4,470	5,514
Interest cost on projected benefit obligation	4,338	3,848
Expected return on plan assets	(12,032)	(12,133)
Net amortization and deferrals	2,972	3,923
Net periodic benefit income	(252)	1,152
Total expense	1,299	2,449
Defined Contribution and Other Retirement Plans [Member] | U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Defined contribution and other retirement plans	2,690	2,255
Defined Contribution and Other Retirement Plans [Member] | Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Defined contribution and other retirement plans	$ 1,551	$ 1,297