Statements Of Consolidated Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Statement of Income and Comprehensive Income [Abstract]
Net Income	$ 41,800	$ 29,422	$ 67,446	$ 36,344
Other Comprehensive Income:
Foreign currency translation adjustment	(1,456)	709	(726)	1,703
Unrealized gain (loss) on available-for-sale security, net of deferred tax of $82, $10, $37 and $14, respectively	(127)	(16)	(57)	21
Employee benefit plans
Amortization of actuarial loss included in expense, net of deferred tax of $1,903, $941, $3,761 and $1,952, respectively	2,931	1,472	5,882	3,054
Other Comprehensive Income	1,348	2,165	5,099	4,778
Comprehensive Income	$ 43,148	$ 31,587	$ 72,545	$ 41,122