Employee Benefits - Amounts Recognized in Balance Sheet (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Other assets	$ 70,792	$ 4,343
Retirement liabilities	(228,936)	(243,407)
U.S Plans [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Other assets	33,164	4,343
Other current liabilities	(4,049)	(4,027)
Retirement liabilities	(49,981)	(51,684)
Net amount recognized	(20,866)	(51,368)
Non-U.S. Plans [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Other assets	38,095	0
Other current liabilities	(652)	(557)
Retirement liabilities	(80,694)	(102,871)
Net amount recognized	$ (43,251)	$ (103,428)