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	$ 733,993	$ 623,925	$ 599,114
Other comprehensive income, net of tax
Foreign currency translation adjustment	(18,009)	1,400	(5,616)
Derivative financial instruments	2,157	(10,144)	18,219
Marketable securities	(953)	350	460
Pension and postretirement benefit plans	291,807	(122,551)	(123,574)
Total other comprehensive income (loss), net of tax	275,002	(130,945)	(110,511)
Comprehensive income	$ 1,008,995	$ 492,980	$ 488,603