Accumulated Other Comprehensive Income (Loss) - Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	$ 232,067	$ 219,925
Tax (benefit) expense	7,985	8,844
Total reclassifications for the period, net of tax	(12,494)	(11,350)
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	4,743	4,505
Tax (benefit) expense	(1,845)	(1,752)
Total reclassifications for the period, net of tax	2,898	2,753
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	5,175	4,809
Tax (benefit) expense	(2,013)	(1,870)
Total reclassifications for the period, net of tax	3,162	2,939
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	(432)	(304)
Tax (benefit) expense	168	118
Total reclassifications for the period, net of tax	$ (264)	$ (186)