Accumulated Other Comprehensive Income (Loss) - Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	$ 257,338	$ 250,565	$ 515,383	$ 495,297
Tax (benefit) expense	22,463	17,530	34,459	27,672
Total reclassifications for the period, net of tax	(33,401)	(25,694)	(51,124)	(40,791)
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	5,190	4,358	10,265	9,058
Tax (benefit) expense	(2,019)	(1,696)	(3,993)	(3,524)
Total reclassifications for the period, net of tax	3,171	2,662	6,272	5,534
Actuarial Losses Recognized | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	5,620	4,786	11,145	9,936
Tax (benefit) expense	(2,186)	(1,862)	(4,335)	(3,865)
Total reclassifications for the period, net of tax	3,434	2,924	6,810	6,071
Prior Service Costs Recognized | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	(430)	(428)	(880)	(878)
Tax (benefit) expense	167	166	342	341
Total reclassifications for the period, net of tax	$ (263)	$ (262)	$ (538)	$ (537)