Bank Premises and Equipment (Detail) - USD ($) $ in Millions		Jun. 30, 2015	Dec. 31, 2014
Bank Premises And Equipment [Abstract]
Land and improvements	[1]	$ 715	$ 793
Buildings		1,750	1,807
Equipment		1,676	1,682
Leasehold improvements		410	416
Construction in Progress		61	98
Land held for sale		61	23
Buildings held for sale		17	3
Equipment held for sale		3
Leasehold improvements held for sale		3
Accumulated depreciation and amortization		(2,398)	(2,357)
Total	[2]	$ 2,298	$ 2,465

[1] At June 30, 2015 and December 31, 2014, land and improvements included $106 million and $165 million, respectively, associated with parcels of undeveloped land intended for future branch expansion.

[2] Includes $84 and $26 of bank premises and equipment held for sale at June 30, 2015 and December 31, 2014, respectively. For further information refer to Note 7.