Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Federal
Current			$ 1	$ 57	$ (49)
Deferred			403	361	401
State
Current			62	15	25
Deferred			(8)	33	(6)
Foreign
Current			9	7	4
Deferred			(4)	0	0
Total income tax expense			463	473	375
Income tax expense in the consolidated statements of operations:
Attributable to income			463	473	375
Stockholders' equity:
Compensation expense for tax purposes in excess of amounts recognized for financial reporting purposes			14	18	13
Tax effect of the change in accumulated other comprehensive loss			554	(434)	(535)
Reconciliation of the statutory federal income tax rate to effective income tax rate
Statutory federal income tax rate (as a percent)			35.00%	35.00%	35.00%
State income taxes, net of federal income tax benefit (as a percent)			2.80%	2.50%	1.30%
Impairments of goodwill (as a percent)			188.50%	0.00%	0.00%
Reversal of liability for unrecognized tax position (as a percent)			(24.50%)	0.00%	0.00%
Foreign income taxes (as a percent)			2.70%	0.30%	0.40%
Nondeductible accounting adjustment for life insurance (as a percent)			3.10%	0.00%	0.00%
Release state valuation allowance (as a percent)			(2.30%)	0.00%	0.00%
Other, net (as a percent)			1.40%	0.00%	2.90%
Effective income tax rate (as a percent)			206.70%	37.80%	39.60%
Impairment	0	1,100	1,092	0	0
Reversal of valuation allowance				16
Deferred tax asset valuation allowance from future income of a special character					8
Deferred tax assets
Post-retirement and pension benefit costs	1,618		1,618	2,311
Deferred Tax Assets, Operating Loss Carryforwards	1,532		1,532	2,176
Other employee benefits	182		182	184
Other	782		782	789
Gross deferred tax assets	4,114		4,114	5,460
Less valuation allowance	(435)		(435)	(444)
Net deferred tax assets	3,679		3,679	5,016
Deferred tax liabilities
Property, plant and equipment, primarily due to depreciation differences	(3,904)		(3,904)	(3,784)
Goodwill and other intangible assets	(3,226)		(3,226)	(3,688)
Other	(137)		(137)	(192)
Gross deferred tax liabilities	(7,267)		(7,267)	(7,664)
Net deferred tax liabilities	(3,588)		(3,588)	(2,648)
Long-term deferred tax liability	4,753		4,753	3,564
Deferred Tax Assets, Net, Current	1,165		1,165	916
Summary of reconciliation of the change in gross unrecognized tax benefits activity
Unrecognized tax benefits, beginning of year			78	111
Increase in tax positions taken in the current year			0	3
Decrease due to the reversal of tax positions taken in a prior year			0	(34)
Decrease from the lapse of statute of limitations			(36)	(2)
Settlements			(28)	0
Unrecognized tax benefits, end of year	14		14	78	111
Valuation Allowance, Deferred Tax Asset, Change in Amount			9
federal
Reconciliation of the statutory federal income tax rate to effective income tax rate
Refund from taxing authority	33		33
Expense on reversal of valuation allowance on auction rate securities			22
Reversal of valuation allowance					12
Summary of reconciliation of the change in gross unrecognized tax benefits activity
Increase in tax positions taken in the current year			17
Valuation Allowance, Deferred Tax Asset, Change in Amount			$ (5)		$ 16