Changes in Accumulated Other Comprehensive Income by Component (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
Accumulated other comprehensive income (loss)	$ (143,252)	$ (99,453)
Other comprehensive income before reclassifications to consolidated statements of income	(65,243)	(61,223)
Amounts reclassified from accumulated other comprehensive (loss) income to the consolidated statements of income	7,667	17,424
Total other comprehensive loss, net of tax	(57,576)	(43,799)	$ (125,397)
Accumulated other comprehensive income (loss)	(200,828)	(143,252)	(99,453)
Gains and Losses on Cash Flow Hedges
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
Accumulated other comprehensive income (loss)	115	(732)
Other comprehensive income before reclassifications to consolidated statements of income	(739)	(70)
Amounts reclassified from accumulated other comprehensive (loss) income to the consolidated statements of income	397	917
Total other comprehensive loss, net of tax	(342)	847
Accumulated other comprehensive income (loss)	(227)	115	(732)
Pension and Other Postretirement Benefit Items
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
Accumulated other comprehensive income (loss)	(105,703)	(115,289)
Other comprehensive income before reclassifications to consolidated statements of income	(16,137)	(6,921)
Amounts reclassified from accumulated other comprehensive (loss) income to the consolidated statements of income	7,270	16,507
Total other comprehensive loss, net of tax	(8,867)	9,586
Accumulated other comprehensive income (loss)	(114,570)	(105,703)	(115,289)
Foreign Currency Items
Changes in Accumulated Other Comprehensive Income by Component [Roll Forward]
Accumulated other comprehensive income (loss)	(37,664)	16,568
Other comprehensive income before reclassifications to consolidated statements of income	(48,367)	(54,232)
Amounts reclassified from accumulated other comprehensive (loss) income to the consolidated statements of income	0	0
Total other comprehensive loss, net of tax	(48,367)	(54,232)
Accumulated other comprehensive income (loss)	$ (86,031)	$ (37,664)	$ 16,568