Fair Value Option - Components of Gain (Loss) on Debt Designated at Fair Value and Related Derivatives (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Mark-to-market on debt designated at fair value :
Interest rate component	[1]	$ 6	$ 49
Credit risk component	[1]	11	26
Total mark-to-market on debt designated at fair value	[1]	17	75
Mark-to-market on the related derivatives	[1],[2]	(9)	(77)
Net realized gains on the related derivatives	[1]	16	61
Gain on debt designated at fair value and related derivatives		24	59
Foreign currency translation gains (losses) recorded in derivatives		(66)	291
Offsetting gains (losses) recorded in derivative related income (expense)		$ 66	$ (291)

[1] The derivatives associated with debt designated at fair value are economic hedges but do not qualify for hedge accounting. See Note 7, "Derivative Financial Instruments," for additional discussion of these non-qualifying hedges.

[2] Mark-to-market on debt designated at fair value and related derivatives excludes market value changes due to fluctuations in foreign currency exchange rates. Foreign currency translation gains (losses) recorded in derivative related expense associated with debt designated at fair value was a loss of $66 million and a gain of $291 million for the three months ended March 31, 2016 and 2015, respectively. Offsetting gains (losses) recorded in derivative related expense associated with the related derivatives was a gain of $66 million and a loss of $291 million for the three months ended March 31, 2016 and 2015, respectively.