Bank Premises & Equipment (Bank Premises and Equipment) (Detail) - USD ($) $ in Millions		Sep. 30, 2017	Dec. 31, 2016
Bank Premises and Equipment
Land and improvements	[1]	$ 643	$ 663
Buildings	[1]	1,676	1,672
Equipment		1,828	1,761
Leasehold improvements		396	398
Construction in progress	[1]	99	99
Land and improvements held for sale		24	29
Buildings held for sale		11	9
Equipment held for sale		1	1
Accumulated depreciation and amortization		(2,660)	(2,567)
Total bank premises and equipment	[2]	$ 2,018	$ 2,065

[1] (a ) At September 30, 2017 and December 31, 2016 , land and improvements , buildings and construction in progress included $ 91 and $ 92 , respectively, associated w it h parcels of undeveloped land intended for future branch expansion.

[2] Includes $ 36 and $ 39 of bank premises and equipment held for sale at September 30, 2017 and December 31, 2016 , respectively. For further information refer to Note 7 .