Pension and OPEB Pension and OPEB Liability Disclosures (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
EERP REIMBURSEMENT			$ 7,973
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost			17,457,000	14,485,000	12,332,000
Interest cost			37,744,000	37,150,000	35,483,000
Expected return on plan assets			(38,522,000)	(36,977,000)	(36,631,000)
Amortization of prior service cost (credits)			(666,000)	(735,000)	(1,109,000)
Amortization of actuarial gain			38,102,000	31,870,000	22,263,000
Net periodic (benefit) cost			54,115,000	45,793,000	32,338,000
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation	857,352,000		857,352,000	701,152,000	654,022,000
service cost - prior year				14,491,000
Defined Benefit Plan, Plan Amendments			(7,186,000)	682,000
Defined Benefit Plan, Business Combinations and Acquisitions, Benefit Obligation			0	900,000
Defined Benefit Plan, Contributions by Plan Participants			0	0
Defined Benefit Plan, Benefits Paid			(51,135,000)	(60,099,000)
Defined Benefit Plan, Actuarial Net (Gains) Losses			159,320,000	54,006,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Fair Value of Plan Assets	582,571,000		582,571,000	537,721,000	462,000,000
Defined Benefit Plan, Actual Return on Plan Assets			23,791,000	63,444,000
Defined Benefit Plan, Contributions by Employer			72,194,000	72,376,000
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent	(269,069,000)		(269,069,000)	(161,173,000)
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities	(5,713,000)		(5,713,000)	(2,258,000)
Defined Benefit Plan, Amounts Recognized in Balance Sheet	(274,782,000)		(274,782,000)	(163,431,000)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	494,622,000		494,622,000	358,674,000
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax	(8,244,000)		(8,244,000)	(1,725,000)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax	486,378,000		486,378,000	356,949,000
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Defined Benefit Plan, Amortization of Net Prior Service Cost (Credit)		(1,630,000)
Defined Benefit Plan, Amortization of Net Gains (Losses)		49,049,000
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets [Abstract]
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Accumulated Benefit Obligation	782,820,000		782,820,000	629,433,000
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Projected Benefit Obligation	857,352,000		857,352,000	701,152,000
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets	582,571,000		582,571,000	537,721,000
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.50%		4.50%	5.30%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	3.80%		3.80%	3.70%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets			8.00%	8.00%	8.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase			3.70%	4.10%	4.10%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate			5.30%	5.80%	6.30%
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	50,902,000		50,902,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	51,922,000		51,922,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	53,247,000		53,247,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	56,114,000		56,114,000
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	293,606,000		293,606,000
Defined Benefit Plan, Expected Future Benefit Payments in Year One	50,778,000		50,778,000
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost			13,677,000	13,147,000	12,654,000
Interest cost			179,739,000	162,815,000	151,451,000
Expected return on plan assets			0	0	0
Amortization of prior service cost (credits)			(46,397,000)	(46,415,000)	(46,415,000)
Amortization of actuarial gain			105,364,000	70,145,000	50,357,000
Net periodic (benefit) cost			252,383,000	199,692,000	168,047,000
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation	3,242,200,000		3,242,200,000	3,257,199,000	2,844,093,000
Defined Benefit Plan, Plan Amendments			0	204,000
Defined Benefit Plan, Business Combinations and Acquisitions, Benefit Obligation			0	2,800,000
Defined Benefit Plan, Contributions by Plan Participants			6,088,000	4,802,000
Defined Benefit Plan, Benefits Paid			(162,853,000)	(170,780,000)
Defined Benefit Plan, Actuarial Net (Gains) Losses			(51,650,000)	400,118,000
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Fair Value of Plan Assets	0		0	0	0
Defined Benefit Plan, Actual Return on Plan Assets			0	0
Defined Benefit Plan, Contributions by Employer			156,765,000	165,978,000
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent	(3,059,671,000)		(3,059,671,000)	(3,077,390,000)
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities	(182,529,000)		(182,529,000)	(179,809,000)
Defined Benefit Plan, Amounts Recognized in Balance Sheet	(3,242,200,000)		(3,242,200,000)	(3,257,199,000)
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	1,328,077,000		1,328,077,000	1,485,090,000
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax	(75,546,000)		(75,546,000)	(121,943,000)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax	1,252,531,000		1,252,531,000	1,363,147,000
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Defined Benefit Plan, Amortization of Net Prior Service Cost (Credit)		(46,397,000)
Defined Benefit Plan, Amortization of Net Gains (Losses)		81,380,000
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.50%		4.50%	5.30%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	0.00%		0.00%	0.00%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets	0.00%			0.00%	0.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	0.00%			0.00%	0.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	5.30%			5.90%	6.20%
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year			6.90%	8.50%	8.70%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate			4.50%	4.50%	4.50%
Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate	2026		2026	2023	2023
Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract]
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components			24,909,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components			(20,876,000)
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation			410,191,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation			(349,038,000)
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	187,606,000		187,606,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	191,429,000		191,429,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	194,995,000		194,995,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	198,422,000		198,422,000
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	989,306,000		989,306,000
Defined Benefit Plan, Expected Future Benefit Payments in Year One	182,529,000		182,529,000
Other Postretirement Benefit Plans, Defined Benefit [Member] | PPACA Legislation [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Plan Amendments			$ 11,800	$ 12,300