Loans and Leases Classified by Primary Purpose (Detail) - USD ($) $ in Millions		Sep. 30, 2015	Dec. 31, 2014
Loans and leases held for sale:
Loans and leases held for sale	[1]	$ 994	$ 1,261
Portfolio loans and leases:
Commercial and industrial loans		42,948	40,765
Commercial mortgage loans		7,061	7,399
Commercial construction loans		3,101	2,069
Commercial leases		3,898	3,720
Total commercial loans and leases		57,008	53,953
Residential mortgage loans		13,392	12,389
Home equity		8,427	8,886
Automobile loans		11,826	12,037
Credit card		2,229	2,401
Other consumer loans and leases		692	418
Total consumer loans and leases		36,566	36,131
Portfolio loans and leases	[2],[3]	93,574	90,084
Commercial Portfolio Segment | Commercial and industrial loans
Loans and leases held for sale:
Loans and leases held for sale		22	36
Commercial Portfolio Segment | Commercial mortgage loans
Loans and leases held for sale:
Loans and leases held for sale		23	11
Commercial Portfolio Segment | Commercial construction loans
Loans and leases held for sale:
Loans and leases held for sale			2
Commercial Portfolio Segment | Commercial leases
Loans and leases held for sale:
Loans and leases held for sale		3	1
Residential Mortgage Loans | Residential mortgage loans
Loans and leases held for sale:
Loans and leases held for sale		805	1,193
Consumer Portfolio Segment | Home equity
Loans and leases held for sale:
Loans and leases held for sale		33
Consumer Portfolio Segment | Automobile Loans
Loans and leases held for sale:
Loans and leases held for sale		3
Consumer Portfolio Segment | Credit Card
Loans and leases held for sale:
Loans and leases held for sale		101
Consumer Portfolio Segment | Other consumer loans and leases
Loans and leases held for sale:
Loans and leases held for sale		$ 4	$ 18

[1] Includes $617 and $561 of residential mortgage loans held for sale measured at fair value at September 30, 2015 and December 31, 2014, respectively.

[2] Includes $137 and $179 of cash and due from banks, $2,179 and $3,378 of portfolio loans and leases, $(27) and $(22) of ALLL, $18 and $25 of other assets, $3 and $5 of other liabilities, and $2,136 and $3,434 of long-term debt from consolidated VIEs that are included in their respective captions above at September 30, 2015 and December 31, 2014, respectively. For further information refer to Note 11.

[3] Includes $173 and $108 of residential mortgage loans measured at fair value at September 30, 2015 and December 31, 2014, respectively.