Statements of Consolidated Comprehensive Income (Loss) Statements of Consolidated Comprehensive Income (Loss) (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statement of Income and Comprehensive Income (Parenthetical) [Abstract]
Unrealized gain(loss) on available-for-sale security, net of deferred tax	$ 145	$ 4	$ 19
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax	1,903	104,425	34,886
OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	7,969	4,373	3,709
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Benefit Plan Improvement, Tax Effect	17,577	0	77
OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditTax	$ 465	$ 468	$ 464