Income Taxes (Narrative) (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Non Variable Interest Entities [Line Items]
Net deferred tax asset	$ 950,000,000
Gross deferred tax asset	986,000,000
Gross deferred tax liability	36,000,000
Unrecognized tax benefits income tax penalties and interest expense	2,000,000
NOL carryforward	3,400,000,000	2,800,000,000
Alternative minimum tax credit carryforward		22,000,000
Non Variable Interest Entities [Member]
Non Variable Interest Entities [Line Items]
Valuation allowance	$ 7,000,000	$ 93,000,000