Accumulated Other Comprehensive Income (Loss) - Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	$ 233,773	$ 220,791	$ 678,647	$ 652,950
Tax (benefit) expense	20,815	18,946	48,929	39,100
Total reclassifications for the period, net of tax	(30,536)	(28,719)	(70,993)	(58,624)
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	4,420	6,840	13,259	20,520
Tax (benefit) expense	(1,719)	(2,661)	(5,158)	(7,983)
Total reclassifications for the period, net of tax	2,701	4,179	8,101	12,537
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	4,727	7,042	14,180	21,124
Tax (benefit) expense	(1,839)	(2,740)	(5,517)	(8,219)
Total reclassifications for the period, net of tax	2,888	4,302	8,663	12,905
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	(307)	(202)	(921)	(604)
Tax (benefit) expense	120	79	359	236
Total reclassifications for the period, net of tax	$ (187)	$ (123)	$ (562)	$ (368)