Defined Contribution Plans, Pension and Other Post-Retirement Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S. Pension and Other Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 116	$ 126	$ 135
Interest cost	1,810	1,878	1,864
Expected return on plan assets	(2,684)	(2,719)	(2,673)
Amortization of prior service cost	6	6	6
Recognized actuarial loss (gain)	21	308	336
Net periodic (benefit) cost	(731)	(401)	(332)
Non-U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0
Interest cost	1,138	1,370	1,470
Expected return on plan assets	(1,196)	(1,520)	(1,597)
Amortization of prior service cost	0	0	0
Recognized actuarial loss (gain)	312	210	275
Net periodic (benefit) cost	$ 254	$ 60	$ 148