Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]
Net income	$ 185,413	$ 151,346	$ 193,173
Other comprehensive income (loss), net of tax:
Changes in net prior service credit and actuarial losses, net of tax provision (benefit) of $42,822, $(3,337) and $(16,045), respectively	66,754	(6,466)	(25,602)
Change in fair value of derivatives, net of tax provision (benefit) of $2,763, $(513) and $(65), respectively	3,937	(905)	(127)
Foreign currency translation, net of tax benefit (provision) of $4,580, $3,309 and $(6,469), respectively	1,103	12,740	(26,527)
Other comprehensive income (loss)	71,794	5,369	(52,256)
Comprehensive income	$ 257,207	$ 156,715	$ 140,917