Carrying Amounts and Estimated Fair Values for Certain Financial Instruments (Detail) (USD $) In Millions	Jun. 30, 2011		Dec. 31, 2010		Jun. 30, 2010		Dec. 31, 2009
Financial assets:
Cash and due from banks	$ 2,380	[1]	$ 2,159	[1]	$ 2,216	[1]	$ 2,318
Held-to-maturity securities	344	[2]	353		354
Other short-term investments	1,370	[1]	1,515	[1]	4,322	[1]
Loans held for sale	978		1,892		1,747
Portfolio loans and leases:
Commercial and industrial loans	28,099		27,191		26,008
Commercial mortgage loans	10,233	[1]	10,845	[1]	11,481	[1]
Commercial construction loans	1,778		2,048		2,965
Commercial leases	3,326		3,378		3,271
Residential mortgage loans	9,849	[3]	8,956	[3]	7,707	[3]
Home equity	11,048	[1]	11,513	[1]	11,987	[1]
Automobile loans	11,315	[1]	10,983	[1]	10,285	[1]
Credit card	1,856		1,896		1,841
Other consumer loans and leases	463		681		687
Financial liabilities:
Federal funds purchased	403		279		240
Carrying (Reported) Amount, Fair Value Disclosure
Financial assets:
Cash and due from banks	2,380		2,159		2,216
Other securities	841		868		894
Held-to-maturity securities	344		353		354
Other short-term investments	1,370		1,515		4,322
Loans held for sale	207		324		403
Portfolio loans and leases:
Commercial and industrial loans	27,022		26,068		24,688
Commercial mortgage loans	9,748		10,248		10,681
Commercial construction loans	1,670		1,890		2,657
Commercial leases	3,232		3,267		3,166
Residential mortgage loans	9,522	[4]	8,600	[5]	7,304	[6]
Home equity	10,817		11,248		11,703
Automobile loans	11,254		10,910		10,173
Credit card	1,720		1,738		1,650
Other consumer loans and leases	439		622		663
Unallocated allowance for loan and lease losses	(130)		(150)		(187)
Total portfolio loans and leases, net	75,294	[4]	74,441	[5]	72,498	[6]
Financial liabilities:
Deposits	80,598		81,648		82,115
Federal funds purchased	403		279		240
Other short-term borrowings	2,702		1,574		1,556
Long-term debt	10,152		9,558		10,989
Portion at Fair Value, Fair Value Disclosure
Financial assets:
Cash and due from banks	2,380		2,159		2,216
Other securities	841		868		894
Held-to-maturity securities	344		353		354
Other short-term investments	1,370		1,515		4,322
Loans held for sale	207		324		403
Portfolio loans and leases:
Commercial and industrial loans	28,447		27,322		26,138
Commercial mortgage loans	9,252		9,513		9,901
Commercial construction loans	1,328		1,471		2,119
Commercial leases	2,917		2,934		2,882
Residential mortgage loans	8,617	[4]	7,577	[5]	6,675	[6]
Home equity	9,660		9,366		9,712
Automobile loans	11,301		10,975		10,407
Credit card	1,795		1,786		1,722
Other consumer loans and leases	482		682		687
Total portfolio loans and leases, net	73,799	[4]	71,626	[5]	70,243	[6]
Financial liabilities:
Deposits	80,770		81,860		82,308
Federal funds purchased	403		279		240
Other short-term borrowings	2,702		1,574		1,556
Long-term debt	$ 10,675		$ 9,921		$ 10,961

[1] Includes $42, $52, and $74 of cash, $7, $7 and $7 of other short-term investments, $29, $29 and $0 of commercial mortgage loans, $231, $241 and $252 of home equity loans, $424, $648 and $911 of automobile loans, ($11), ($14) and ($16) of ALLL, $4, $7 and $7 of other assets, $8, $12 and $19 of other liabilities and $365, $692 and $996 of long-term debt from consolidated VIEs that are included in their respective captions above at June 30, 2011, December 31, 2010 and June 30, 2010, respectively. See Note 8.

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

[3] Includes $59, $46 and $41 of residential mortgage loans measured at fair value at June 30, 2011, December 31, 2010 and June 30, 2010, respectively.

[4] Excludes $59 of residential mortgage loans measured at fair value on a recurring basis.

[5] Excludes $46 of residential mortgage loans measured at fair value on a recurring basis.

[6] Excludes $41 of residential mortgage loans measured at fair value on a recurring basis.