Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 826,609	$ 796,479
Ending Balance	842,041	826,609
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(58,253)	(36,315)
Pre-tax amount	1,346	(22,158)
Foreign currency translation	16	220
Ending Balance	(56,891)	(58,253)
Unrealized Gain (Loss) on Net Investment Hedge [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	1,046	1,046
Ending Balance	1,046	1,046
Unrealized Gain (Loss) on Cash Flow Hedging Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(1,864)	2,471
Pre-tax amount	1,183	(4,287)
Tax (provision) benefit		84
Reclassification of (gain) loss to net income	511	6
Foreign currency translation	(22)	(138)
Ending Balance	(192)	(1,864)
Unrealized Actuarial Gain (Loss) Related to Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	2,256	1,574
Pre-tax amount		783
Tax (provision) benefit	3	47
Reclassification of (gain) loss to net income	(24)	(66)
Foreign currency translation	6	(82)
Ending Balance	2,241	2,256
Unrealized Gain (Loss) on Postretirement Obligation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	40	120
Reclassification of (gain) loss to net income	(5)	(80)
Ending Balance	35	40
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(56,775)	(31,104)
Pre-tax amount	2,529	(25,662)
Tax (provision) benefit	3	131
Reclassification of (gain) loss to net income	482	(140)
Ending Balance	$ (53,761)	$ (56,775)