Loans and Leases Classified by Primary Purpose (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Loans and leases held for sale:
Commercial and industrial loans	$ 39		$ 45
Commercial mortgage loans	13		76
Commercial construction loans	9		17
Residential mortgage loans	2,856		2,802
Other consumer loans and leases	22		14
Total loans and leases held for sale	2,939		2,954
Portfolio loans and leases:
Commercial and industrial loans	36,038		30,783
Commercial mortgage loans	9,103	[1]	10,138	[1]
Commercial construction loans	698		1,020
Commercial leases	3,549		3,531
Total commercial loans and leases	49,388		45,472
Residential mortgage loans	12,017	[2]	10,672	[2]
Home equity	10,018	[1]	10,719	[1]
Automobile loans	11,972	[1]	11,827	[1]
Credit card	2,097		1,978
Other consumer loans and leases	290		350
Total consumer loans and leases	36,394		35,546
Portfolio loans and leases	$ 85,782		$ 81,018

[1] At December 31, 2012 and 2011, includes $0 and $30 of cash, $0 and $7 of other short-term investments, $50 and $50 of commercial mortgage loans, $0 and $223 of home equity loans, $0 and $259 of automobile loans, ($5) and ($10) of ALLL, $3 and $4 of other assets, $0 and $4 of other liabilities, $0 and $191 of long-term debt from consolidated VIEs that are included in their respective captions. See Note 10.

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