Mortgage Banking Activity - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Mortgage Banking [Line Items]
Net loans and leases	$ 55,905		$ 55,905		$ 54,189
Mortgage banking and title income	34	$ 38	56	$ 91
Mortgage banking and title income
Mortgage Banking [Line Items]
Mortgage banking and title income			3	$ 1
Sale of mortgage servicing rights	21
Gain on sale of mortgage servicing rights	12
First Horizon Bank
Mortgage Banking [Line Items]
Net loans and leases	$ 41		$ 41