Loans and Leases Classified by Primary Purpose (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Loans and leases held for sale:
Commercial and industrial loans	$ 25		$ 39
Commercial mortgage loans	11		13
Commercial construction loans	5		9
Residential mortgage loans	2,622		2,856
Other consumer loans and leases	28		22
Total loans and leases held for sale	2,691		2,939
Portfolio loans and leases:
Commercial and industrial loans	36,757		36,038
Commercial mortgage loans	8,766	[1]	9,103	[1]
Commercial construction loans	694		698
Commercial leases	3,568		3,549
Total commercial loans and leases	49,785		49,388
Residential mortgage loans	12,091	[2]	12,017	[2]
Home equity	9,727		10,018
Automobile loans	11,741		11,972
Credit card	2,043		2,097
Other consumer loans and leases	289		290
Total consumer loans and leases	35,891		36,394
Portfolio loans and leases	$ 85,676		$ 85,782

[1] Includes $50 and $50 of commercial mortgage loans, $(13) and $(5) of ALLL, $1 and $3 of other assets from consolidated VIEs that are included in their respective captions above at March 31, 2013 and December 31, 2012, respectively. See Note 8.

[2] Includes $81 and $76 of residential mortgage loans measured at fair value at March 31, 2013 and December 31, 2012, respectively.