Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	$ (12,468)	$ (20,939)
Other comprehensive income (loss) before reclassifications	[1]	504	2,794
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	0	(182)
Other comprehensive income (loss)	[1]	504	2,612
Ending balance	[1]	(11,964)	(18,327)
Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	0	(111)
Other comprehensive income (loss) before reclassifications	[1]	0	60
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	0	0
Other comprehensive income (loss)	[1]	0	60
Ending balance	[1]	0	(51)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	(11,002)	(12,041)
Other comprehensive income (loss) before reclassifications	[1]	514	2,505
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	0	0
Other comprehensive income (loss)	[1]	514	2,505
Ending balance	[1]	(10,488)	(9,536)
Investment in Debt Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	0	126
Other comprehensive income (loss) before reclassifications	[1]	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	0	(126)
Other comprehensive income (loss)	[1]	0	(126)
Ending balance	[1]	0	0
Defined Benefit Plan Items
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	(1,466)	(8,913)
Other comprehensive income (loss) before reclassifications	[1]	(10)	229
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	0	(56)
Other comprehensive income (loss)	[1]	(10)	173
Ending balance	[1]	$ (1,476)	$ (8,740)

[1] All amounts are net of tax. Amounts in parentheses indicate debits