Statements of Consolidated Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Income	$ 137,039	$ 99,153	$ 104,546
Foreign currency translation adjustment	(2,731)	871	481
Unrealized gain (loss) on available-for-sale security, net of deferred tax of $0, $0 and $145, respectively	0	0	226
Actuarial gain (loss), net of deferred tax of $59,850, $103,308 and $1,903, respectively	(96,329)	161,631	(2,977)
Net actuarial loss included in net periodic benefit expense or income, net of deferred tax of $9,432, $7,562 and $7,969, respectively	14,940	11,827	12,465
Prior-service cost or credit, net of deferred tax of $0, $7,505 and $17,577, respectively	0	11,738	(27,493)
Amortization of prior service cost or credit included in net periodic benefit expense or income, net of deferred tax of $481, $552 and $465, respectively	(758)	863	(727)
Employee benefit plans	(82,147)	186,059	(18,732)
Total Other Comprehensive (Income) Loss	(84,878)	186,930	(18,025)
Comprehensive Income (Loss)	$ 52,161	$ 286,083	$ 86,521