Available-for-Sale and Held-to-Maturity Securities (Detail) (USD $) In Millions	Jun. 30, 2011		Dec. 31, 2010		Jun. 30, 2010
Investment Holdings [Line Items]
Amortized Cost	$ 14,889	[1]	$ 14,919		$ 15,356
Unrealized Gains	623		542		681
Total Unrealized Losses	(10)		(47)		(16)
Fair Value	15,502	[1],[2]	15,414	[2]	16,021	[2]
Amortized Cost	344	[1],[3]	353	[3]	354	[3]
Unrealized Gains
Unrealized Losses
Fair Value	344	[1]	353		354
US Treasury and Government
Investment Holdings [Line Items]
Amortized Cost	199		225		475
Unrealized Gains	7		5		7
Fair Value	206		230		482
US Government-sponsored Enterprises Debt Securities
Investment Holdings [Line Items]
Amortized Cost	2,141		1,564		1,692
Unrealized Gains	118		81		104
Fair Value	2,259		1,645		1,796
US States and Political Subdivisions Debt Securities
Investment Holdings [Line Items]
Amortized Cost	113		170		196
Unrealized Gains	2		2		3
Fair Value	115		172		199
Amortized Cost	340		348		349
Unrealized Gains
Unrealized Losses
Fair Value	340		348		349
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Investment Holdings [Line Items]
Amortized Cost	10,269		10,570		10,109
Unrealized Gains	475		435		539
Total Unrealized Losses	(4)		(32)		(1)
Fair Value	10,740		10,973		10,647
Other Debt Securities
Investment Holdings [Line Items]
Amortized Cost	1,135		1,338		946
Unrealized Gains	17		19		28
Total Unrealized Losses	(6)		(15)		(15)
Fair Value	1,146		1,342		959
Amortized Cost	4		5		5
Unrealized Gains
Unrealized Losses
Fair Value	4		5		5
Equity Securities, Other
Investment Holdings [Line Items]
Amortized Cost	1,032	[4]	1,052	[4]	1,938	[4]
Unrealized Gains	4	[4]
Fair Value	$ 1,036	[4]	$ 1,052	[4]	$ 1,938	[4]

[1] Actual maturities may differ from contractual maturities when there exists a right to call or prepay obligations with or without call or prepayment penalties.

[2] Amortized cost of $14,889, $14,919 and $15,356 at June 30, 2011, December 31, 2010 and June 30, 2010, respectively.

[3] Fair value of $344, $353 and $354 at June 30, 2011, December 31, 2010 and June 30, 2010, respectively.

[4] Other securities consist of FHLB and FRB restricted stock holdings of $497 and $344, respectively at June 30, 2011, $524 and $344, respectively at December 31, 2010, and $551 and $343, respectively, at June 30, 2010, that are carried at cost, and certain mutual fund and equity security holdings.