Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011		Jun. 30, 2011
Assets:
Available For Sale Securities	$ 14,709	[1]	$ 14,520	[1]	$ 14,661	[1]
Trading securities	200		177		217
Residential mortgage loans held for sale	1,788		2,751		978
Residential mortgage loans	76	[2]	65	[2]	59	[2]
Derivative assets	2,307		2,356		1,964
Total assets	19,080		19,869		17,879
Liabilities:
Derivative liabilities	1,096		1,344		1,157
Short positions	10		6		12
Total liabilities	1,106		1,350		1,169
US Treasury and Government
Assets:
Available For Sale Securities	51		171		206
US Government Agencies Debt Securities
Assets:
Available For Sale Securities	1,966		1,962		2,259
US States and Political Subdivisions Debt Securities
Assets:
Available For Sale Securities	211		101		115
Trading securities	14		9		38
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Assets:
Available For Sale Securities	9,279		10,284		10,740
Trading securities	19		11		33
Other Debt Securities
Assets:
Available For Sale Securities	2,811		1,812		1,146
Trading securities	11		13		11
Equity Securities, Other
Assets:
Available For Sale Securities	391	[1]	190	[1]	195	[1]
Trading securities	156		144		135
Interest Rate Contract
Assets:
Derivative assets	1,736		1,815		1,478
Liabilities:
Derivative liabilities	733		858		775
Foreign Exchange Contract
Assets:
Derivative assets	237		294		295
Liabilities:
Derivative liabilities	221		275		283
Equity Contract
Assets:
Derivative assets	214		113		106
Liabilities:
Derivative liabilities	30		81		21
Commodity Contract
Assets:
Derivative assets	120		134		85
Liabilities:
Derivative liabilities	112		130		78
Fair Value, Inputs, Level 1
Assets:
Available For Sale Securities	131	[1]	356	[1]	394	[1]
Trading securities	156		144		135
Derivative assets	9		8		6
Total assets	296		508		535
Liabilities:
Derivative liabilities	37		54		9
Short positions	9		2		6
Total liabilities	46		56		15
Fair Value, Inputs, Level 1 | US Treasury and Government
Assets:
Available For Sale Securities	51		171		206
Fair Value, Inputs, Level 1 | Equity Securities, Other
Assets:
Available For Sale Securities	80	[1]	185	[1]	188	[1]
Trading securities	156		144		135
Fair Value, Inputs, Level 1 | Interest Rate Contract
Assets:
Derivative assets	9		8		6
Liabilities:
Derivative liabilities	37		54		9
Fair Value, Inputs, Level 2
Assets:
Available For Sale Securities	14,578		14,164		14,267
Trading securities	43		32		81
Residential mortgage loans held for sale	1,788		2,751		978
Derivative assets	2,029		2,201		1,843
Total assets	18,438		19,148		17,169
Liabilities:
Derivative liabilities	1,028		1,207		1,123
Short positions	1		4		6
Total liabilities	1,029		1,211		1,129
Fair Value, Inputs, Level 2 | US Government Agencies Debt Securities
Assets:
Available For Sale Securities	1,966		1,962		2,259
Fair Value, Inputs, Level 2 | US States and Political Subdivisions Debt Securities
Assets:
Available For Sale Securities	211		101		115
Trading securities	13		8		37
Fair Value, Inputs, Level 2 | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Assets:
Available For Sale Securities	9,279		10,284		10,740
Trading securities	19		11		33
Fair Value, Inputs, Level 2 | Other Debt Securities
Assets:
Available For Sale Securities	2,811		1,812		1,146
Trading securities	11		13		11
Fair Value, Inputs, Level 2 | Equity Securities, Other
Assets:
Available For Sale Securities	311		5		7
Fair Value, Inputs, Level 2 | Interest Rate Contract
Assets:
Derivative assets	1,672		1,773		1,463
Liabilities:
Derivative liabilities	695		802		762
Fair Value, Inputs, Level 2 | Foreign Exchange Contract
Assets:
Derivative assets	237		294		295
Liabilities:
Derivative liabilities	221		275		283
Fair Value, Inputs, Level 2 | Commodity Contract
Assets:
Derivative assets	120		134		85
Liabilities:
Derivative liabilities	112		130		78
Fair Value, Inputs, Level 3
Assets:
Trading securities	1		1		1
Residential mortgage loans	76	[2]	65	[2]	59	[2]
Derivative assets	269		147		115
Total assets	346		213		175
Liabilities:
Derivative liabilities	31		83		25
Total liabilities	31		83		25
Fair Value, Inputs, Level 3 | US States and Political Subdivisions Debt Securities
Assets:
Trading securities	1		1		1
Fair Value, Inputs, Level 3 | Interest Rate Contract
Assets:
Derivative assets	55		34		9
Liabilities:
Derivative liabilities	1		2		4
Fair Value, Inputs, Level 3 | Equity Contract
Assets:
Derivative assets	214		113		106
Liabilities:
Derivative liabilities	$ 30		$ 81		$ 21

[1] Excludes FHLB and FRB restricted stock totaling $497 and $346, respectively, at June 30, 2012, $497 and $345, respectively, at December 31, 2011, and $497 and $344, respectively at June 30, 2011.

[2] Includes residential mortgage loans originated as held for sale and subsequently transferred to held for investment. (c) During the three months ended June 30, 2012, no assets or liabilities were transferred between Level 1 and Level 2