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Income Taxes (Narrative) (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Non Variable Interest Entities [Line Items]
Net deferred tax asset	$ 1,000,000,000
Gross deferred tax liability	28,000,000
Unrecognized Tax Benefits Income Tax Penalties And Interest Expense	2,000,000
Valuation allowance	12,000,000	93,000,000
NOL carryforward	3,200,000,000	2,800,000,000
Alternative minimum tax credit carryforward		$ 22,000,000

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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