Gross Realized Gains and Losses on Sales and OTTI on Securities Available for Sale (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Gross realized gains	$ 0		$ 3
Available-for-sale Securities, Gross Realized Losses	(1)		0
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	0		(1)
Gain (Loss) on Sale of Securities, Net	$ (1)	[1]	$ 2	[1]

[1] Total OTTI was $0 for the three months ended March 31, 2014 and 2013. Of total OTTI, losses of $0 and $1 million were recognized in earnings, and gains of $0 and $1 million were recognized as non-credit-related OTTI in OCI for the three months ended March 31, 2014 and 2013, respectively.