Changes in Accumulated Other Comprehensive Loss by Component - Reconciliation of Changes in Accumulated Other Comprehensive Loss by Component (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Gain/(Loss) by Component, beginning balance			$ (49,864)	$ (76,086)
Net current-period Other Comprehensive Income Gain/(Loss)			(6,863)	14,484
Reclassification adjustment from loss on partial settlement of pension plan, net of tax	$ 0	$ 0	3,815	0
Accumulated Other Comprehensive Gain/(Loss) by Component, ending balance	(52,912)	(61,602)	(52,912)	(61,602)
Gains and Losses on Cash Flow Hedges [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Gain/(Loss) by Component, beginning balance			(452)	(646)
Net current-period Other Comprehensive Income Gain/(Loss)			1,078	657
Reclassification adjustment from loss on partial settlement of pension plan, net of tax			0
Accumulated Other Comprehensive Gain/(Loss) by Component, ending balance	626	11	626	11
Defined Benefit Pension Plans [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Gain/(Loss) by Component, beginning balance			(3,678)	(5,668)
Net current-period Other Comprehensive Income Gain/(Loss)			577	(171)
Reclassification adjustment from loss on partial settlement of pension plan, net of tax			3,815
Accumulated Other Comprehensive Gain/(Loss) by Component, ending balance	714	(5,839)	714	(5,839)
Cumulative Foreign Currency Translation Adjustment [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Gain/(Loss) by Component, beginning balance			(45,734)	(69,772)
Net current-period Other Comprehensive Income Gain/(Loss)			(8,518)	13,998
Reclassification adjustment from loss on partial settlement of pension plan, net of tax			0
Accumulated Other Comprehensive Gain/(Loss) by Component, ending balance	$ (54,252)	$ (55,774)	$ (54,252)	$ (55,774)