Supplemental Cash Flow (Noncash Investing and Financing Activities) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash Payments:
Interest	$ 1,441	$ 1,016	$ 699
Income taxes	726	359	1,035
Transfers:
Portfolio loans to loans held for sale	211	275	255
Loans held for sale to portfolio loans	37	95	29
Portfolio loans to OREO	29	39	34
Supplemental Disclosures:
Conversion of outstanding preferred stock issued by a Bancorp subsidiary	197	0	0
Additions to right-of-use assets under operating leases	76	0	0
Additions to right-of-use assets under finance leases	24	0	0
Right-of-use assets recognized at adoption of ASU 2016-02	$ 509	$ 0	$ 0