Impacts of Derivative Financial Instruments on the Consolidated Statements of Income/(Loss) and the Consolidated Statements of Shareholders' Equity (Additional Information) (Detail) - Derivatives, by Derivative Instrument Contract [Domain] - Derivative Contract Type [Domain] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Interest Income (Expense), Net [Member]
Reclassified in pre-tax gains from AOCI into net interest income	$ 19	$ 27	$ 38	$ 54
Not Designated as Hedging Instrument [Member]
Derivative, Gain (Loss) on Derivative, Net	$ (86)	$ 93	$ 120	$ 198