Components of Net Periodic Pension Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	434	438	867	875
Return on assets (expected)	(224)	(199)	(448)	(397)
Amortization of net actuarial loss	138	136	276	272
Net periodic pension cost (benefit)	348	375	695	750
Foreign Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	154	173	308	346
Interest cost	113	151	226	302
Return on assets (expected)	(75)	(68)	(150)	(136)
Amortization of net actuarial loss	0	0	0	(1,897)
Net periodic pension cost (benefit)	$ 192	$ 256	$ 384	$ (1,385)