v3.26.1
Components of Other Comprehensive Income (Loss) - Schedule of Changes in AOCI (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Beginning balance $ 9,465 $ 9,142 $ 9,044 $ 9,111 $ 9,142 $ 9,111
Other comprehensive income (loss) (14) (22) 71 145 (36) 216
Ending balance 9,463 9,465 9,257 9,044 9,463 9,257
Total            
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Beginning balance (832) [1] (810) [1] (983) [2] (1,128) [2] (810) [1] (1,128) [2]
Net unrealized gains (losses) (22)   60   (53) 194
Amounts reclassified from AOCI 8   11   17 22
Other comprehensive income (loss) (14) [1] (22) [1] 71 [2] 145 [2] (36) 216
Ending balance (846) [1] (832) [1] (912) [2] (983) [2] (846) [1] (912) [2]
Securities AFS            
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Beginning balance (526) (512) (666) (782) (512) (782)
Net unrealized gains (losses) (9)   53   (23) 169
Amounts reclassified from AOCI 0   0   0 0
Other comprehensive income (loss) (9)   53   (23) 169
Ending balance (535) (526) (613) (666) (535) (613)
Cash Flow Hedges            
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Beginning balance (52) (42) (67) (94) (42) (94)
Net unrealized gains (losses) (13)   7   (30) 25
Amounts reclassified from AOCI 6   9   13 18
Other comprehensive income (loss) (7)   16   (17) 43
Ending balance (59) (52) (51) (67) (59) (51)
Pension and Postretirement Plans            
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Beginning balance (254) (256) (250) (252) (256) (252)
Net unrealized gains (losses) 0   0   0 0
Amounts reclassified from AOCI 2   2   4 4
Other comprehensive income (loss) 2   2   4 4
Ending balance $ (252) $ (254) $ (248) $ (250) $ (252) $ (248)
[1] Due to the nature of the preferred stock issued by FHN and its subsidiaries, all components of other comprehensive income (loss) have been attributed solely to FHN as the controlling interest holder.
[2] Due to the nature of the preferred stock issued by FHN and its subsidiaries, all components of other comprehensive income (loss) have been attributed solely to FHN as the controlling interest holder.