Changes in Accumulated Other Comprehensive Income by Component (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
Accumulated other comprehensive income (loss)	$ (99,453)	$ 25,944
Other comprehensive income before reclassifications to consolidated statements of income	(61,223)	(133,386)
Amounts reclassified from accumulated other comprehensive (loss) income to the consolidated statements of income	17,424	7,989
Total other comprehensive (loss) income, net of tax	(43,799)	(125,397)	$ 92,696
Accumulated other comprehensive income (loss)	(143,252)	(99,453)	25,944
Gains and Losses on Cash Flow Hedges
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
Accumulated other comprehensive income (loss)	(732)	(519)
Other comprehensive income before reclassifications to consolidated statements of income	(70)	(1,074)
Amounts reclassified from accumulated other comprehensive (loss) income to the consolidated statements of income	917	861
Total other comprehensive (loss) income, net of tax	847	(213)
Accumulated other comprehensive income (loss)	115	(732)	(519)
Pension and Other Postretirement Benefit Items
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
Accumulated other comprehensive income (loss)	(115,289)	(73,273)
Other comprehensive income before reclassifications to consolidated statements of income	(6,921)	(49,144)
Amounts reclassified from accumulated other comprehensive (loss) income to the consolidated statements of income	16,507	7,128
Total other comprehensive (loss) income, net of tax	9,586	(42,016)
Accumulated other comprehensive income (loss)	(105,703)	(115,289)	(73,273)
Foreign Currency Items
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
Accumulated other comprehensive income (loss)	16,568	99,736
Other comprehensive income before reclassifications to consolidated statements of income	(54,232)	(83,168)
Amounts reclassified from accumulated other comprehensive (loss) income to the consolidated statements of income	0	0
Total other comprehensive (loss) income, net of tax	(54,232)	(83,168)
Accumulated other comprehensive income (loss)	$ (37,664)	$ 16,568	$ 99,736