Defined Contribution Plans, Pension and Other Post-Retirement Benefit Plans - Change in Benefit Obligation Plan Assets and Funded Status (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in plan assets:
Fair value of plan assets — Beginning of the year	$ 69,470
Fair value of plan assets at end of the year	80,423	$ 69,470
U.S. Pension and Other Post-Retirement Benefit Plans
Change in benefit obligation:
Benefit obligation — Beginning of the year	47,512	47,795
Service cost	116	126	$ 135
Interest cost	1,810	1,878	1,864
Participant contributions	8	7
Benefits paid	(2,188)	(2,161)
Actuarial loss (gain)	2,814	(133)
Exchange rate changes	0	0
Benefit obligation at end of the year	50,072	47,512	47,795
Change in plan assets:
Fair value of plan assets — Beginning of the year	38,390	36,270
Actual return on plan assets	6,584	2,035
Employer contributions	2,252	2,239
Participant contributions	8	7
Benefits paid	(2,188)	(2,161)
Exchange rate changes	0	0
Fair value of plan assets at end of the year	45,046	38,390	36,270
Funded status	(5,026)	(9,122)
Non-U.S. Pension Plans
Change in benefit obligation:
Benefit obligation — Beginning of the year	40,820	39,186
Service cost	0	0	0
Interest cost	1,138	1,370	1,470
Participant contributions	0	0
Benefits paid	(1,309)	(1,454)
Actuarial loss (gain)	1,099	9,234
Exchange rate changes	3,989	(7,516)
Benefit obligation at end of the year	45,737	40,820	39,186
Change in plan assets:
Fair value of plan assets — Beginning of the year	31,080	33,608
Actual return on plan assets	1,798	4,214
Employer contributions	747	756
Participant contributions	0	0
Benefits paid	(1,309)	(1,454)
Exchange rate changes	3,061	(6,044)
Fair value of plan assets at end of the year	35,377	31,080	$ 33,608
Funded status	$ (10,360)	$ (9,740)