Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	$ (55,159)	$ (27,023)	$ (54,595)	$ (21,181)
Other comprehensive income (loss) before reclassifications	[1]	(2,215)	(863)	(2,609)	(6,535)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	(85)	(85)	(255)	(255)
Other comprehensive income (loss)	[1]	(2,300)	(948)	(2,864)	(6,790)
Ending balance	[1]	(57,459)	(27,971)	(57,459)	(27,971)
Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	(242)	(506)	(364)	(637)
Other comprehensive income (loss) before reclassifications	[1]	62	79	184	210
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	0	0	0	0
Other comprehensive income (loss)	[1]	62	79	184	210
Ending balance	[1]	(180)	(427)	(180)	(427)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	(7,913)	0	(4,709)	0
Other comprehensive income (loss) before reclassifications	[1]	(2,750)	0	(5,954)	0
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	0	0	0	0
Other comprehensive income (loss)	[1]	(2,750)	0	(5,954)	0
Ending balance	[1]	(10,663)	0	(10,663)	0
Investment in Debt Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	126	2,399	126	7,861
Other comprehensive income (loss) before reclassifications	[1]	0	(1,214)	0	(6,676)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	0	0	0	0
Other comprehensive income (loss)	[1]	0	(1,214)	0	(6,676)
Ending balance	[1]	126	1,185	126	1,185
Defined Benefit Plan Items
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance	[1]	(47,130)	(28,916)	(49,648)	(28,405)
Other comprehensive income (loss) before reclassifications	[1]	473	272	3,161	(69)
Amounts reclassified from accumulated other comprehensive income (loss)	[1]	(85)	(85)	(255)	(255)
Other comprehensive income (loss)	[1]	388	187	2,906	(324)
Ending balance	[1]	$ (46,742)	$ (28,729)	$ (46,742)	$ (28,729)

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