Consolidated Balance Sheets (Parenthetical) - USD ($)	Jun. 30, 2022	Dec. 31, 2021
Fair Value	$ 7,880,000,000	$ 7,665,000,000
Financing receivable, unearned income	325,000,000	373,000,000
Aggregate amount of certificates of deposit	$ 100,000	$ 100,000
Common shares, par value (in usd per share)	$ 1	$ 1
Common shares, shares authorized (in shares)	2,100,000,000	2,100,000,000
Common shares, shares issued (in shares)	1,256,702,081	1,256,702,081
Treasury stock, shares (in shares)	324,059,544	327,852,311
Residential Mortgage
Loans held for sale	$ 83,000,000	$ 281,000,000