Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Common stock, par value (in dollars per share)	$ 5	$ 5
Common stock, authorized (shares)	800,000,000	800,000,000
Common stock, issued (shares)	543,000,000	543,000,000
Common stock held in treasury at cost (shares)	145,000,000	142,000,000
Preferred stock, par value	$ 0.5	$ 0.5
Portion at Fair Value, Fair Value Disclosure
Loans held for sale, fair value	800.0	900.0
Loans, fair value	1,300.0	1,300.0
Other assets, fair value	100.0	100.0
Other borrowed funds, fair value (less than)	100.0	100.0
Other liabilities	$ 100.0	$ 200.0