Consolidated Statements Of Comprehensive Income (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$ 623,925,000	$ 599,114,000	$ 146,545,000
Other comprehensive income, net of tax
Foreign currency translation adjustment	1,400,000	(5,616,000)	9,449,000
Derivative financial instruments:
Unrealized net gains (losses) arising during the period	(513,000)	(966,000)	(7,852,000)
Net losses (gains) reclassified into net income	(9,631,000)	19,185,000	4,880,000
Total derivative financial instruments	(10,144,000)	18,219,000	(2,972,000)
Marketable securities:
Unrealized gains (losses) on marketable securities	350,000	460,000	(133,000)
Net (gains) losses reclassified into net income	0	0	0
Total marketable securities	350,000	460,000	(133,000)
Pension and postretirement benefit plans:
Amortization of net prior service (credit) cost	(563,000)	(564,000)	925,000
Amortization of actuarial loss	32,295,000	23,584,000	20,944,000
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	(158,213,000)	(146,768,000)	18,431,000
Actuarial loss reclassified into net income due to settlement	3,930,000	173,000	2,942,000
Prior service credit (cost) reclassified into net income due to net curtailment loss	0	1,000	(1,393,000)
Total pension and postretirement benefit plans	122,551,000	123,574,000	(41,849,000)
Total other comprehensive (loss) income, net of tax	(130,945,000)	(110,511,000)	48,193,000
Comprehensive income	$ 492,980,000	$ 488,603,000	$ 194,738,000