Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Assets:
Available for sale and other securities	$ 18,597	[1]	$ 15,207	[1]
Trading securities	343		207
Residential mortgage loans held for sale	890		2,856
Derivative assets	1,553		1,972
Fair value, recurring
Assets:
Available for sale and other securities	17,846	[2]	14,363	[2]
Trading securities	343		207
Residential mortgage loans held for sale	890		2,856
Residential mortgage loans	92	[3]	76	[3]
Derivative assets	1,553		1,972
Total assets	20,724		19,474
Liabilities:
Derivative liabilities	754		915
Short positions	8		10
Total liabilities	762		925
Interest Rate Contract | Fair value, recurring
Assets:
Derivative assets	827		1,507
Liabilities:
Derivative liabilities	389		617
Foreign Exchange Contract | Fair value, recurring
Assets:
Derivative assets	276		201
Liabilities:
Derivative liabilities	252		183
Equity Contract | Fair value, recurring
Assets:
Derivative assets	384		177
Liabilities:
Derivative liabilities	48		33
Commodity Contract | Fair value, recurring
Assets:
Derivative assets	66		87
Liabilities:
Derivative liabilities	65		82
US Treasury and Government | Fair value, recurring
Assets:
Available for sale and other securities	26		41
Trading securities	1		1
US Government Agencies Debt Securities | Fair value, recurring
Assets:
Available for sale and other securities	1,644		1,911
Trading securities	4		6
US States and Political Subdivisions Debt Securities | Fair value, recurring
Assets:
Available for sale and other securities	192		212
Trading securities	13		17
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises | Fair value, recurring
Assets:
Available for sale and other securities	12,284		8,730
Trading securities	3		7
Other Debt Securities | Fair value, recurring
Assets:
Available for sale and other securities	3,582		3,277
Trading securities	7		15
Other Debt and Equity Securities | Fair value, recurring
Assets:
Available for sale and other securities	118	[2]	192	[2]
Trading securities	315		161
Fair Value, Inputs, Level 1 | Fair value, recurring
Assets:
Available for sale and other securities	115	[2],[4]	120	[2],[4]
Trading securities	316	[4]	162	[4]
Derivative assets	31	[4]	2	[4]
Total assets	462	[4]	284	[4]
Liabilities:
Derivative liabilities	10	[4]	14	[4]
Short positions	4	[4]	8	[4]
Total liabilities	14	[4]	22	[4]
Fair Value, Inputs, Level 1 | Interest Rate Contract | Fair value, recurring
Assets:
Derivative assets	13	[4]	2	[4]
Liabilities:
Derivative liabilities	1	[4]	14	[4]
Fair Value, Inputs, Level 1 | Commodity Contract | Fair value, recurring
Assets:
Derivative assets	18	[4]
Liabilities:
Derivative liabilities	9	[4]
Fair Value, Inputs, Level 1 | US Treasury and Government | Fair value, recurring
Assets:
Available for sale and other securities	26	[4]	41	[4]
Trading securities	1	[4]	1	[4]
Fair Value, Inputs, Level 1 | Other Debt and Equity Securities | Fair value, recurring
Assets:
Available for sale and other securities	89	[2],[4]	79	[2],[4]
Trading securities	315	[4]	161	[4]
Fair Value, Inputs, Level 2 | Fair value, recurring
Assets:
Available for sale and other securities	17,731	[2],[4]	14,243	[2],[4]
Trading securities	26	[4]	44	[4]
Residential mortgage loans held for sale	890	[4]	2,856	[4]
Derivative assets	1,126	[4]	1,733	[4]
Total assets	19,773	[4]	18,876	[4]
Liabilities:
Derivative liabilities	692	[4]	865	[4]
Short positions	4	[4]	2	[4]
Total liabilities	696	[4]	867	[4]
Fair Value, Inputs, Level 2 | Interest Rate Contract | Fair value, recurring
Assets:
Derivative assets	802	[4]	1,445	[4]
Liabilities:
Derivative liabilities	384	[4]	600	[4]
Fair Value, Inputs, Level 2 | Foreign Exchange Contract | Fair value, recurring
Assets:
Derivative assets	276	[4]	201	[4]
Liabilities:
Derivative liabilities	252	[4]	183	[4]
Fair Value, Inputs, Level 2 | Commodity Contract | Fair value, recurring
Assets:
Derivative assets	48	[4]	87	[4]
Liabilities:
Derivative liabilities	56	[4]	82	[4]
Fair Value, Inputs, Level 2 | US Government Agencies Debt Securities | Fair value, recurring
Assets:
Available for sale and other securities	1,644	[4]	1,911	[4]
Trading securities	4	[4]	6	[4]
Fair Value, Inputs, Level 2 | US States and Political Subdivisions Debt Securities | Fair value, recurring
Assets:
Available for sale and other securities	192	[4]	212	[4]
Trading securities	12	[4]	16	[4]
Fair Value, Inputs, Level 2 | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises | Fair value, recurring
Assets:
Available for sale and other securities	12,284	[4]	8,730	[4]
Trading securities	3	[4]	7	[4]
Fair Value, Inputs, Level 2 | Other Debt Securities | Fair value, recurring
Assets:
Available for sale and other securities	3,582	[4]	3,277	[4]
Trading securities	7	[4]	15	[4]
Fair Value, Inputs, Level 2 | Other Debt and Equity Securities | Fair value, recurring
Assets:
Available for sale and other securities	29	[2],[4]	113	[2],[4]
Fair Value, Inputs, Level 3 | Fair value, recurring
Assets:
Trading securities	1		1
Residential mortgage loans	92	[3]	76	[3]
Derivative assets	396		237
Total assets	489		314
Liabilities:
Derivative liabilities	52		36
Total liabilities	52		36
Fair Value, Inputs, Level 3 | Interest Rate Contract | Fair value, recurring
Assets:
Derivative assets	12		60
Liabilities:
Derivative liabilities	4		3
Fair Value, Inputs, Level 3 | Equity Contract | Fair value, recurring
Assets:
Derivative assets	384		177
Liabilities:
Derivative liabilities	48		33
Fair Value, Inputs, Level 3 | US States and Political Subdivisions Debt Securities | Fair value, recurring
Assets:
Trading securities	$ 1		$ 1

[1] Amortized cost of $18,409 and $ 14,571 at December 31, 2013 and 2012, respectively.

[2] Excludes FHLB and FRB restricted stock totaling $402 and $349, respectively, at December 31, 2013 and $497 and $347, respectively, at December 31, 2012.

[3] Includes residential mortgage loans originated as held for sale and subsequently transferred to held for investment

[4] During the years ended December 31, 2013 and 2012, no assets or liabilities were transferred between Level 1 and Level 2.