Postretirement Benefits Other Than Pensions - Schedule of Postretirement Benefit Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Funded status of the plans		$ 8,034
U.S. Other Postretirement Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligations at beginning of year	$ 33,955	37,753
Service cost	361	434	$ 422
Interest cost	1,383	1,411	1,589
Actuarial loss (gain)	112	(3,937)
Benefits paid	(1,939)	(1,731)
Other	5	25	25
Foreign currency exchange rate effect	0	0
Benefit obligation at end of year	33,877	33,955	37,753
Funded status of the plans	(33,877)	(33,955)
Net amount recognized at December 31	(33,877)	(33,955)
Non-U.S. Other Postretirement Benefits [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligations at beginning of year	16,455	19,487
Service cost	372	380	545
Interest cost	678	678	752
Actuarial loss (gain)	926	(266)
Benefits paid	(601)	(595)
Other	0	0	0
Foreign currency exchange rate effect	520	(3,229)
Benefit obligation at end of year	18,350	16,455	$ 19,487
Funded status of the plans	(18,350)	(16,455)
Net amount recognized at December 31	$ (18,350)	$ (16,455)