Detail of Certain Balance Sheet Accounts - Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 747,599	$ 666,519
Other comprehensive income (loss) before reclassifications	(1,218)	6,512
Amounts reclassified from accumulated other comprehensive loss		(1,999)
Other comprehensive income (loss), net of tax	(1,218)	4,513
Ending balance	762,054	692,148
Cumulative Foreign Currency Translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(24,093)	(9,654)
Other comprehensive income (loss) before reclassifications	(4,496)	3,619
Amounts reclassified from accumulated other comprehensive loss		0
Other comprehensive income (loss), net of tax	(4,496)	3,619
Ending balance	(28,589)	(6,035)
Cash Flow Hedges, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	3,922	4,550
Other comprehensive income (loss) before reclassifications	(1,316)	2,893
Amounts reclassified from accumulated other comprehensive loss		(1,999)
Other comprehensive income (loss), net of tax	(1,316)	894
Ending balance	2,606	5,444
Net Investment Hedges, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	6,153	(1,926)
Other comprehensive income (loss) before reclassifications	4,594	0
Amounts reclassified from accumulated other comprehensive loss		0
Other comprehensive income (loss), net of tax	4,594	0
Ending balance	10,747	(1,926)
Benefit Plans Liability, Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(77,681)	(91,265)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive loss		0
Other comprehensive income (loss), net of tax	0	0
Ending balance	(77,681)	(91,265)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(91,699)	(98,295)
Ending balance	$ (92,917)	$ (93,782)