Loans and Leases Classified by Primary Purpose (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011		Sep. 30, 2011
Loans and leases held for sale:
Commercial and industrial loans	$ 13		$ 45		$ 66
Commercial mortgage loans	20		76		105
Commercial construction loans	11		17		26
Residential mortgage loans	1,741		2,802		1,629
Other consumer loans and leases	17		14		14
Total loans and leases held for sale	1,802		2,954		1,840
Portfolio loans and leases:
Commercial and industrial loans	33,344		30,783		29,258
Commercial mortgage loans	9,348	[1]	10,138	[1]	10,330	[1]
Commercial construction loans	672		1,020		1,213
Commercial leases	3,549		3,531		3,368
Total commercial loans and leases	46,913		45,472		44,169
Residential mortgage loans	11,708	[2]	10,672	[2]	10,249	[2]
Home equity	10,238	[1]	10,719	[1]	10,920	[1]
Automobile loans	11,912	[1]	11,827	[1]	11,593	[1]
Credit card	1,994		1,978		1,878
Other consumer loans and leases	294		350		407
Total consumer loans and leases	36,146		35,546		35,047
Portfolio loans and leases	$ 83,059		$ 81,018		$ 79,216

[1] Includes $0, $30 and $35 of cash, $0, $7 and $7of other short-term investments, $50, $50 and $29 of commercial mortgage loans, $0, $223 and $228 of home equity loans, $0, $259 and $334 of automobile loans, ($2), ($10) and ($10) of ALLL, $3, $4 and $3 of other assets, $0, $4 and $5 of other liabilities, $0, $191and $270 of long-term debt from consolidated VIEs that are included in their respective captions above at September 30, 2012, December 31, 2011 and September 30, 2011, respectively. See Note 8.

[2] Includes $76, $65 and $62 of residential mortgage loans measured at fair value at September 30, 2012, December 31, 2011 and September 30, 2011, respectively.