Pension and OPEB Pension and OPEB Liability Disclosures (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Service Cost		$ (32,164,000)	$ (53,853,000)	$ (47,792,000)
Net periodic (benefit) cost		93,799,000	52,446,000	71,470,000
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Actuarial Net (Gains) Losses		86,481,000	106,299,000	119,262,000
Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax		(367,610,000)	(824,103,000)
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.57%		4.51%
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost		20,865,000	20,466,000	17,457,000
Interest cost		36,829,000	37,586,000	37,744,000
Expected return on plan assets		(51,814,000)	(46,157,000)	(38,522,000)
Defined Benefit Plan, Service Cost		(1,611,000)	(1,630,000)	(666,000)
Amortization of actuarial gain		37,853,000	47,834,000	38,102,000
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments		(374,000)	0	0
Defined Benefit Plan, Net Periodic Benefit Cost		39,482,000	0	0
Net periodic (benefit) cost		81,230,000	58,099,000	54,115,000
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation		812,644,000	953,102,000	857,352,000
service cost - prior year			20,466,000
Defined Benefit Plan, Plan Amendments		0	0
Defined Benefit Plan, Curtailments		(6,551,000)	0
Defined Benefit Plan, Settlements, Benefit Obligation		86,925,000	0
Defined Benefit Plan, Contributions by Plan Participants		0	0
Defined Benefit Plan, Benefits Paid		(21,958,000)	(52,804,000)
Defined Benefit Plan, Actuarial Net (Gains) Losses		(82,718,000)	90,502,000
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax		231,000
Deferred Income Taxes and Tax Credits		143,000
Defined Benefit Plan, Settlements, Plan Assets		(86,925,000)	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Fair Value of Plan Assets		768,831,000	728,161,000	582,571,000
Defined Benefit Plan, Actual Return on Plan Assets		94,084,000	87,935,000
Defined Benefit Plan, Contributions by Employer		55,469,000	110,459,000
Defined Benefit Plan, Assets for Plan Benefits, Noncurrent		9,032,000	0
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent		(48,252,000)	(218,004,000)
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities		(4,593,000)	(6,937,000)
Defined Benefit Plan, Amounts Recognized in Balance Sheet		(43,813,000)	(224,941,000)
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		286,637,000	495,511,000
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax		(4,629,000)	(6,614,000)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax		282,008,000	488,897,000
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year [Abstract]
Defined Benefit Plan, Amortization of Net Prior Service Cost (Credit)		(1,384,000)
Defined Benefit Plan, Amortization of Net Gains (Losses)		23,564,000
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		50,820,000	895,493,000
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Projected Benefit Obligation		52,845,000	953,102,000
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets		0	728,161,000
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate		4.87%	4.00%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase		4.23%	3.77%
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		7.75%	8.00%	8.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase		3.77%	3.82%	3.66%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate		4.00%	4.50%	5.30%
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
Defined Benefit Plan, Expected Future Benefit Payments in Year Two		50,080,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Three		48,952,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Four		49,415,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Five		50,741,000
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter		262,986,000
Defined Benefit Plan, Expected Future Benefit Payments in Year One		90,347,000
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost		18,680,000	18,817,000	13,677,000
Interest cost		111,687,000	135,695,000	179,739,000
Expected return on plan assets		0	0	0
Defined Benefit Plan, Service Cost		(30,552,000)	(51,828,000)	(46,397,000)
Amortization of actuarial gain		66,417,000	80,875,000	105,364,000
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments		(39,650,000)	0	0
Defined Benefit Plan, Net Periodic Benefit Cost		(1,348,129,000)	0	0
Net periodic (benefit) cost		(1,221,547,000)	183,559,000	252,383,000
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Benefit Obligation		1,021,974,000	3,018,172,000	3,242,200,000
Defined Benefit Plan, Plan Amendments		0	(80,570,000)
Defined Benefit Plan, Curtailments		0	0
Defined Benefit Plan, Settlements, Benefit Obligation		1,891,057,000	0
Defined Benefit Plan, Contributions by Plan Participants		6,150,000	5,651,000
Defined Benefit Plan, Benefits Paid		(168,026,000)	(172,471,000)
Defined Benefit Plan, Actuarial Net (Gains) Losses		(73,632,000)	(131,150,000)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax		339,318,000
Deferred Income Taxes and Tax Credits		203,610,000
Defined Benefit Plan, Settlements, Plan Assets		0	0
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Defined Benefit Plan, Fair Value of Plan Assets		0	0	0
Defined Benefit Plan, Actual Return on Plan Assets		0	0
Defined Benefit Plan, Contributions by Employer		161,876,000	166,820,000
Defined Benefit Plan, Assets for Plan Benefits, Noncurrent		0	0
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent		(961,127,000)	(882,600,000)
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities		(60,847,000)	(58,452,000)
Defined Benefit Plan, Amounts Recognized in Balance Sheet		(1,021,974,000)	(3,018,172,000)
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		433,073,000	1,116,051,000
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax		(34,086,000)	(104,288,000)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax		398,987,000	1,011,763,000
Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year [Abstract]
Defined Benefit Plan, Amortization of Net Prior Service Cost (Credit)		(8,784,000)
Defined Benefit Plan, Amortization of Net Gains (Losses)		25,474,000
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate		4.88%	4.05%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase		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		4.05%	4.51%	5.33%
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year		6.17%	6.30%	6.85%
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	2026
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		17,296,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components		(14,297,000)
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation		123,355,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation		(103,788,000)
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
Defined Benefit Plan, Expected Future Benefit Payments in Year Two		62,914,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Three		65,493,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Four		67,623,000
Defined Benefit Plan, Expected Future Benefit Payments in Year Five		68,395,000
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter		338,544,000
Defined Benefit Plan, Expected Future Benefit Payments in Year One		60,847,000
Other Postretirement Benefit Plan, Defined Benefit [Member] | remeasurent and assumption changes [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Plan Amendments			80,571,000
Other Postretirement Benefit Plan, Defined Benefit [Member] | PPACA Legislation [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Plan Amendments		12,400	3,000,000
Comprehensive Income [Member] | remeasurent and assumption changes [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Plan Amendments			50,276,000
Deferred Tax Asset [Domain] | remeasurent and assumption changes [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Plan Amendments			30,295,000
Other Expense [Member] | remeasurent and assumption changes [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Plan Amendments			9,425,000
Other Postretirement Benefit Plan, Defined Benefit [Member] | Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments		(24,515,000)
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Deferred Income Taxes and Tax Credits		$ 15,135,000