Supplemental Cash Flow (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020
Cash Payments:
Interest	$ 256	$ 528
Income taxes	336	268
Transfers:
Portfolio loans and leases to loans and leases held for sale	337	31
Loans and leases held for sale to portfolio loans and leases	20	29
Portfolio loans and leases to OREO	9	6
Loans and leases held for sale to OREO	0	2
Bank premises and equipment to OREO	17	0
Supplemental Disclosures:
Net additions to lease liabilities under operating leases	31	27
Net additions to lease liabilities under finance leases	25	76
Accounts, Notes, Loans and Financing Receivable
Portfolio loans and leases to loans and leases held for sale	337	$ 31
Residential mortgage loans \| GNMA loans
Transfers:
Portfolio loans and leases to loans and leases held for sale	139
Accounts, Notes, Loans and Financing Receivable
Portfolio loans and leases to loans and leases held for sale	$ 139

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