Asset Quality - Summary of Allowance for Loan and Lease Losses (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 874	$ 818	$ 824	$ 823
Charge-offs	(61)	(62)	(200)	(177)
Recoveries	14	14	54	57
Provision for loan and lease losses from continuing operations	59	45	200	121
Ending balance	883	813	883	813
Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	854	796	796	794
Charge-offs	(55)	(53)	(179)	(152)
Recoveries	11	12	46	47
Net loans and leases charged off	(44)	(41)	(133)	(105)
Provision for loan and lease losses from continuing operations	56	36	203	102
Foreign currency translation adjustment	(1)	(1)	(1)	(1)
Ending balance	$ 865	$ 790	$ 865	$ 790