Income Taxes (Narrative) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Non Variable Interest Entities [Line Items]
Federal statutory rate	35.00%	35.00%	35.00%
Net deferred tax asset	$ 1,009,000,000	$ 1,109,000,000
Non U.S. deferred tax liability	18,000,000
Valuation allowance	0	93,000,000
Increase in net income (loss)			60,000,000
NOL carryforward	3,200,000,000
Alternative minimum tax credit carryforward	$ 22,000,000	$ 22,000,000