Asset Quality - Summary of Allowance for Loan and Lease Losses (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 824	$ 823	$ 887
Charge-offs	(289)	(238)	(256)
Recoveries	67	74	112
Provision for loan and lease losses from continuing operations	266	166	57
Ending balance	882	824	823
Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	796	794	848
Charge-offs	(261)	(203)	(211)
Recoveries	56	61	98
Net loans and leases charged off	(205)	(142)	(113)
Provision for loan and lease losses from continuing operations	267	145	59
Foreign currency translation adjustment	0	(1)	0
Ending balance	$ 858	$ 796	$ 794