Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (219,205)	$ (33,183)	$ (212,949)	$ (35,036)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	18,359	(281)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(25,151)	1,298
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	536	836
Other Comprehensive Income (Loss), Net of Tax	(6,256)	1,853
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(30,901)	79,260	(4,960)	77,915
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(25,941)	1,345
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Other Comprehensive Income (Loss), Net of Tax	(25,941)	1,345
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax	12,881	(2,231)	(1,944)	(2,433)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	18,359	(281)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(1,547)	43
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(1,987)	440
Other Comprehensive Income (Loss), Net of Tax	14,825	202
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(201,185)	(110,212)	(206,045)	(110,518)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	2,337	(90)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,523	396
Other Comprehensive Income (Loss), Net of Tax	$ 4,860	$ 306