Pension and Other Postretirement Benefits - Contributions for Pension and Other Postretirement Benefits (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Foreign Defined Benefit Pension Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Contributions	$ 896	$ 860
Other Postretirement Benefit Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Contributions	664	305
U.K. Defined Contribution Pension Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Contributions	135	201
U.S. Defined Contribution Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Contributions	$ 1,201	$ 0