Accumulated Other Comprehensive Income - (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Unrealized gains (losses) on securities available-for-sale:
Balance at beginning of period	$ 992		$ 883		$ 97
Other comprehensive income for period:
Net unrealized gains (losses) arising during period, net of tax of $(617) million, $136 million and $605 million, respectively	(897)		194		862
Reclassification adjustment for gains realized in net income (loss), net of tax of $(80) million, $(60) million and $(53) million, respectively	(113)	[1]	(85)	[1]	(76)	[1]
Total other comprehensive loss for period	(1,010)		109		786
Balance at end of period	(18)		992		883
Unrealized gains (losses) on other-than-temporarily impaired debt securities available-for-sale:
Balance at beginning of period	0		0		(1)
Reclassification adjustment for losses realized in net income (loss), net of tax of $1 million in 2011(2)	0	[2]	0	[2]	1	[2]
Total other comprehensive income (loss) for period	0		0		1
Balance at end of period	0		0		0
Unrealized losses on other-than-temporarily impaired debt securities held-to-maturity:
Balance at beginning of period	0		0		(153)
Adjustment to add other-than-temporary impairment due to the consolidation of a VIE, net of tax of $(47) million	(67)		0		0
Reclassification adjustment related to the accretion of unrealized other-than-temporary impairment, net of tax of $4 million	7	[2]	0	[2]	0	[2]
Net unrealized other-than-temporary impairment arising during period	0		0		11
Adjustment to reverse other-than-temporary impairment due to deconsolidation of VIE	0		0		142
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Loss, Net of Tax, Including Portion Attributable to Noncontrolling Interest and VIE, Held-to-maturity Securities	7		0		153
Balance at end of period	(60)		0		0
Unrealized (losses) gains on derivatives classified as cash flow hedges:
Balance at beginning of period	(201)		(229)		(87)
Other comprehensive income (loss) for period:
Net gains (losses) arising during period, net of tax of $78 million, $10 million and $(115) million, respectively	112		18		(150)
Reclassification adjustment for losses realized in net income (loss), net of tax of $4 million, $7 million and $5 million, respectively	6	[3]	10	[3]	8	[3]
Total other comprehensive income (loss) for period	118		28		(142)
Balance at end of period	(83)		(201)		(229)
Pension and postretirement benefit liability:
Balance at beginning of period	(6)		(12)		(9)
Other comprehensive income (loss) for period:
Reclassification adjustment of prior service costs and transition obligations in net income, net of tax of less than $1 million for the three and nine months ended	8		4		(5)
Reclassification adjustment of prior service costs and transition obligations in net income (loss), net of tax of $1 million, $1 million and $2 million, respectively	0	[4]	2	[4]	2	[4]
Total other comprehensive income for period	8		6		(3)
Balance at end of period	2		(6)		(12)
Total accumulated other comprehensive income at end of period	$ (159)		$ 785		$ 642

[1] Amount reclassified to net income (loss) is included in other securities gains, net in our consolidated statement of income (loss).

[2] Amount reclassified to net income (loss) is included in interest income in our consolidated statement of income (loss).

[3] Amount reclassified to net income (loss) is included in interest income (expense) in our consolidated statement of income (loss).

[4] Amount reclassified to net income (loss) is included in salaries and employee benefits in our consolidated statement of income (loss).