Income Taxes (Tables)

12 Months Ended

Dec. 31, 2011

Income Tax Disclosure [Abstract]

Schedule of Income Tax (Expense) Benefit

	Year Ended December 31,
	2011			2010			2009
	(in millions)
Current income tax (expense) benefit
Federal	$	(1	)	$	48		$	279
State	(20		)	15			13
Total current income tax (expense) benefit	(21		)	63			292
Deferred income tax (expense) benefit
Federal	(136		)	(270		)	963
State	(95		)	40			(196		)
Total deferred income tax (expense) benefit	(231		)	(230		)	767
Foreign income tax (expense) benefit	(2		)	1			(1		)
Total income tax (expense) benefit	$	(254	)	$	(166	)	$	1,058

Factors Causing Variation in Effective Tax Rate From US Federal Statutory Rate

	Year Ended December 31,
	2011			2010			2009
	(in millions)
Income tax benefit at the federal statutory rate	$	923		$	1,155		$	1,223
Effect of:
State income taxes, net of federal income tax effect	80			118			93
State law changes, net of federal income tax effect	(38		)	—			(6		)
Reduction in liability for unrecognized tax benefits	(1		)	18			83
Tax expense related to equity awards	(13		)	(42		)	(33		)
Change in valuation allowance	(1,221		)	(1,418		)	(281		)
Other, net	16			3			(21		)
Income tax (expense) benefit	$	(254	)	$	(166	)	$	1,058
Effective income tax rate	(9.6		)%	(5.0		)%	30.3		%

Schedule of Income Tax Expense Benefit Allocated to Other Items

	Year Ended December 31,
	2011			2010		2009
	(in millions)
Unrecognized net periodic pension and other postretirement benefit cost(1)	$	—		$	5	$	(87	)
Unrealized holding gains/losses on securities(1)	(1		)	1		(9		)
Stock ownership, purchase and option arrangements(2)	—			—		(56		)

Schedule of Deferred Income Tax Assets and Liabilities

	December 31, 2011						December 31, 2010
	Current			Long-Term			Current			Long-Term
	(in millions)
Deferred tax assets
Net operating loss carryforwards	$	—		$	3,873		$	—		$	3,318
Capital loss carryforwards	—			52			—			51
Accruals and other liabilities	461			1,094			445			1,073
Tax credit carryforwards	—			471			—			473
Pension and other postretirement benefits	—			324			—			238
	461			5,814			445			5,153
Valuation allowance	(284		)	(3,580		)	(210		)	(2,355		)
	177			2,234			235			2,798
Deferred tax liabilities
Property, plant and equipment	—			1,527			—			1,792
Intangibles	—			6,720			—			6,611
Investments	—			855			—			1,065
Other	47			118			50			132
	47			9,220			50			9,600
Current deferred tax asset	$	130					$	185
Long-term deferred tax liability				$	6,986					$	6,802

Schedule of Unrecognized Tax Benefits

	2011			2010
	(in  millions)
Balance at January 1	$	228		$	284
Additions based on current year tax positions	4			1
Additions based on prior year tax positions	4			13
Reductions for prior year tax positions	(1		)	(21		)
Reductions for settlements	(2		)	(38		)
Reductions for lapse of statute of limitations	(8		)	(11		)
Balance at December 31	$	225		$	228