Pension and Other Post-Retirement Benefit Plans (Detail) - Pension Plan - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
U.S. Pension Plans and Other Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 33	$ 0	$ 66
Interest cost	418	449	836	897
Expected return on plan assets	(787)	(671)	(1,574)	(1,342)
Amortization of prior service cost	2	2	3	3
Recognized actuarial loss	69	89	138	179
Net (benefit) cost	(298)	(98)	(597)	(197)
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	270	283	556	565
Expected return on plan assets	(316)	(295)	(650)	(590)
Amortization of prior service cost	0	0	0	0
Recognized actuarial loss	130	120	267	239
Net (benefit) cost	$ 84	$ 108	$ 173	$ 214