Statements Of Consolidated Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Statement of Other Comprehensive Income [Abstract]
Net Income	$ 14,005	$ 25,646
Other Comprehensive Income (Loss):
Foreign currency translation adjustment	440	730
Unrealized gain on available-for-sale security, net of deferred tax of $0 and $45, respectively	0	70
Employee benefit plans (Note 5)
Net loss included in net periodic benefit expense or income, net of deferred tax of $1,922 and $1,975, respectively	3,007	3,133
Amortization of prior service cost or credit included in net periodic benefit expense or income, net of deferred tax of $61 and $117, respectively	95	(182)
Employee benefit plans	3,102	2,951
Total Other Comprehensive Income	3,542	3,751
Comprehensive Income	$ 17,547	$ 29,397