Other Comprehensive Income (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (266,403)	$ (238,038)	$ (266,649)	$ (212,949)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(8,305)	13,547
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(2,126)	(39,509)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	10,677	873
Other Comprehensive Income (Loss), Net of Tax	246	(25,089)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(57,232)	(45,783)	(57,394)	(4,960)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	162	(40,823)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Other Comprehensive Income (Loss), Net of Tax	162	(40,823)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(4,082)	3,689	3,016	(1,944)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(3,760)	13,547
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(217)	(1,832)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(3,121)	(6,082)
Other Comprehensive Income (Loss), Net of Tax	(7,098)	5,633
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(205,089)	(195,944)	$ (212,271)	$ (206,045)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(4,545)	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(2,071)	3,146
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	13,798	6,955
Other Comprehensive Income (Loss), Net of Tax	$ 7,182	$ 10,101