v3.26.1
Condensed Financial Information of the Parent Company - Condensed Statements of Cash Flows (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
OPERATING ACTIVITIES      
Net income (loss) attributable to Key $ 1,829 $ (161) $ 967
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:      
Other operating activities, net 533 (139) 389
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES 2,208 664 2,903
INVESTING ACTIVITIES      
Net (increase) decrease in securities available for sale and in short-term and other investments 7,341 (6,687) (8,385)
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES 3,219 2,497 1,417
FINANCING ACTIVITIES      
Net proceeds from Scotiabank investment 0 2,771 0
Cash dividends paid (1,054) (927) (911)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES (5,883) (2,359) (4,266)
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS (456) 802 54
CASH AND DUE FROM BANKS AT BEGINNING OF YEAR 1,743 941 887
CASH AND DUE FROM BANKS AT END OF YEAR 1,287 1,743 941
Parent      
OPERATING ACTIVITIES      
Net income (loss) attributable to Key 1,829 (161) 967
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:      
Equity in net (income) loss less dividends from subsidiaries (773) 588 (575)
Other operating activities, net 329 (752) 172
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES 1,385 (325) 564
INVESTING ACTIVITIES      
Net (increase) decrease in securities available for sale and in short-term and other investments (26) (19) (14)
Advances to subsidiaries 0 (250) 0
Sale or repayments of advances to subsidiaries 0 200 16
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES (26) (69) 2
FINANCING ACTIVITIES      
Net proceeds (payments) from issuance of long-term debt (350) 1,000 0
Repurchase of Treasury Shares (236) (28) (73)
Net proceeds from Scotiabank investment 0 2,771 0
Cash dividends paid (1,054) (927) (912)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES (1,640) 2,816 (985)
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS (281) 2,422 (419)
CASH AND DUE FROM BANKS AT BEGINNING OF YEAR 5,149 2,727 3,146
CASH AND DUE FROM BANKS AT END OF YEAR $ 4,868 $ 5,149 $ 2,727