| Consolidated Balance Sheets | |||||||||||||||||
| (dollars in millions) | |||||||||||||||||
| 9/30/2026 | 6/30/2026 | 9/30/2025 | |||||||||||||||
| Assets | |||||||||||||||||
| Loans | $ | 112,993 | $ | 110,430 | $ | 105,902 | |||||||||||
| Loans held for sale | 1,159 | 1,198 | 998 | ||||||||||||||
| Securities available for sale | 36,311 | 38,459 | 40,456 | ||||||||||||||
| Held-to-maturity securities | 9,612 | 9,515 | 7,509 | ||||||||||||||
| Trading account assets | 925 | 936 | 972 | ||||||||||||||
| Short-term investments | 12,973 | 12,416 | 13,334 | ||||||||||||||
| Other investments | 1,281 | 1,230 | 921 | ||||||||||||||
| Total earning assets | 175,254 | 174,184 | 170,092 | ||||||||||||||
| Allowance for loan and lease losses | (1,398) | (1,445) | (1,444) | ||||||||||||||
| Cash and due from banks | 1,540 | 1,711 | 1,938 | ||||||||||||||
| Premises and equipment | 636 | 620 | 606 | ||||||||||||||
| Goodwill | 2,803 | 2,752 | 2,752 | ||||||||||||||
| Other intangible assets | 11 | 3 | 13 | ||||||||||||||
| Corporate-owned life insurance | 4,461 | 4,456 | 4,428 | ||||||||||||||
| Accrued income and other assets | 9,617 | 8,848 | 8,803 | ||||||||||||||
| Discontinued assets | 178 | 188 | 221 | ||||||||||||||
| Total assets | $ | 193,102 | $ | 191,317 | $ | 187,409 | |||||||||||
| Liabilities | |||||||||||||||||
| Deposits in domestic offices: | |||||||||||||||||
| Interest-bearing deposits | 125,594 | 122,196 | 122,425 | ||||||||||||||
| Noninterest-bearing deposits | 28,220 | 30,893 | 28,340 | ||||||||||||||
| Total deposits | 153,814 | 153,089 | 150,765 | ||||||||||||||
| Federal funds purchased and securities sold under repurchase agreements | 49 | 5 | 10 | ||||||||||||||
| Bank notes and other short-term borrowings | 5,185 | 3,680 | 1,339 | ||||||||||||||
| Accrued expense and other liabilities | 4,772 | 3,778 | 4,276 | ||||||||||||||
| Long-term debt | 11,473 | 10,967 | 10,917 | ||||||||||||||
| Total liabilities | 175,293 | 171,519 | 167,307 | ||||||||||||||
| Equity | |||||||||||||||||
| Preferred stock | 1,975 | 2,500 | 2,500 | ||||||||||||||
| Common shares | 1,257 | 1,257 | 1,257 | ||||||||||||||
| Capital surplus | 6,057 | 6,014 | 6,002 | ||||||||||||||
| Retained earnings | 16,194 | 15,873 | 15,111 | ||||||||||||||
| Treasury stock, at cost | (3,809) | (3,492) | (2,619) | ||||||||||||||
| Accumulated other comprehensive income (loss) | (3,865) | (2,354) | (2,149) | ||||||||||||||
| Total equity | 17,809 | 19,798 | 20,102 | ||||||||||||||
| Total liabilities and equity | $ | 193,102 | $ | 191,317 | $ | 187,409 | |||||||||||
| Common shares outstanding (000) | 1,058,176 | 1,072,035 | 1,112,952 | ||||||||||||||
| Consolidated Statements of Income | ||||||||||||||||||||||||||
| (dollars in millions, except per share amounts) | ||||||||||||||||||||||||||
| Three months ended | Nine months ended | |||||||||||||||||||||||||
| 9/30/2026 | 6/30/2026 | 9/30/2025 | 9/30/2026 | 9/30/2025 | ||||||||||||||||||||||
| Interest income | ||||||||||||||||||||||||||
| Loans | $ | 1,511 | $ | 1,463 | $ | 1,466 | $ | 4,390 | $ | 4,310 | ||||||||||||||||
| Loans held for sale | 22 | 15 | 18 | 51 | 43 | |||||||||||||||||||||
| Securities available for sale | 373 | 367 | 408 | 1,110 | 1,211 | |||||||||||||||||||||
| Held-to-maturity securities | 98 | 95 | 64 | 279 | 188 | |||||||||||||||||||||
| Trading account assets | 12 | 10 | 11 | 33 | 44 | |||||||||||||||||||||
| Short-term investments | 107 | 101 | 156 | 311 | 487 | |||||||||||||||||||||
| Other investments | 10 | 8 | 8 | 23 | 25 | |||||||||||||||||||||
| Total interest income | 2,133 | 2,059 | 2,131 | 6,197 | 6,308 | |||||||||||||||||||||
| Interest expense | ||||||||||||||||||||||||||
| Deposits | 634 | 600 | 748 | 1,832 | 2,231 | |||||||||||||||||||||
| Federal funds purchased and securities sold under repurchase agreements | 11 | 19 | 4 | 44 | 9 | |||||||||||||||||||||
| Bank notes and other short-term borrowings | 25 | 35 | 14 | 80 | 75 | |||||||||||||||||||||
| Long-term debt | 163 | 155 | 181 | 469 | 572 | |||||||||||||||||||||
| Total interest expense | 833 | 809 | 947 | 2,425 | 2,887 | |||||||||||||||||||||
| Net interest income | 1,300 | 1,250 | 1,184 | 3,772 | 3,421 | |||||||||||||||||||||
| Provision for credit losses | 61 | 92 | 107 | 259 | 363 | |||||||||||||||||||||
| Net interest income after provision for credit losses | 1,239 | 1,158 | 1,077 | 3,513 | 3,058 | |||||||||||||||||||||
| Noninterest income | ||||||||||||||||||||||||||
| Trust and investment services income | 165 | 159 | 150 | 481 | 435 | |||||||||||||||||||||
| Investment banking and debt placement fees | 214 | 169 | 184 | 580 | 537 | |||||||||||||||||||||
| Service charges on deposit accounts | 79 | 77 | 75 | 233 | 217 | |||||||||||||||||||||
| Operating lease income and other leasing gains | 9 | 10 | 11 | 27 | 34 | |||||||||||||||||||||
| Corporate services income | 72 | 80 | 72 | 223 | 213 | |||||||||||||||||||||
| Cards and payments income | 93 | 94 | 86 | 273 | 253 | |||||||||||||||||||||
| Corporate-owned life insurance income | 35 | 33 | 35 | 102 | 100 | |||||||||||||||||||||
| Consumer mortgage income | 14 | 17 | 14 | 44 | 42 | |||||||||||||||||||||
| Commercial mortgage servicing fees | 53 | 49 | 73 | 164 | 219 | |||||||||||||||||||||
| Other income | 9 | 15 | 8 | 42 | 16 | |||||||||||||||||||||
| Net securities gains (losses) | 1 | 3 | (6) | 4 | (6) | |||||||||||||||||||||
| Total noninterest income | 744 | 706 | 702 | 2,173 | 2,060 | |||||||||||||||||||||
| Noninterest expense | ||||||||||||||||||||||||||
| Personnel | 815 | 786 | 742 | 2,344 | 2,127 | |||||||||||||||||||||
| Net occupancy | 67 | 68 | 65 | 203 | 201 | |||||||||||||||||||||
| Computer processing | 116 | 108 | 105 | 335 | 319 | |||||||||||||||||||||
| Business services and professional fees | 46 | 46 | 44 | 128 | 132 | |||||||||||||||||||||
| Equipment | 21 | 22 | 20 | 62 | 61 | |||||||||||||||||||||
| Operating lease expense | 6 | 7 | 9 | 20 | 30 | |||||||||||||||||||||
| Marketing | 23 | 22 | 22 | 63 | 67 | |||||||||||||||||||||
| Other expense | 151 | 158 | 170 | 488 | 525 | |||||||||||||||||||||
| Total noninterest expense | 1,245 | 1,217 | 1,177 | 3,643 | 3,462 | |||||||||||||||||||||
| Income (loss) from continuing operations before income taxes | 738 | 647 | 602 | 2,043 | 1,656 | |||||||||||||||||||||
| Income taxes | 159 | 139 | 112 | 434 | 337 | |||||||||||||||||||||
| Income (loss) from continuing operations | 579 | 508 | 490 | 1,609 | 1,319 | |||||||||||||||||||||
| Income (loss) from discontinued operations, net of taxes | — | 1 | (1) | 1 | — | |||||||||||||||||||||
| Net income (loss) | 579 | 509 | 489 | 1,610 | 1,319 | |||||||||||||||||||||
| Less: Net income (loss) attributable to noncontrolling interests | — | — | — | — | — | |||||||||||||||||||||
| Net income (loss) attributable to Key | $ | 579 | $ | 509 | $ | 489 | $ | 1,610 | $ | 1,319 | ||||||||||||||||
| Income (loss) from continuing operations attributable to Key common shareholders | $ | 537 | $ | 472 | $ | 454 | $ | 1,495 | $ | 1,211 | ||||||||||||||||
| Net income (loss) attributable to Key common shareholders | 537 | 473 | 453 | 1,496 | 1,211 | |||||||||||||||||||||
| Per common share | ||||||||||||||||||||||||||
| Income (loss) from continuing operations attributable to Key common shareholders | $ | .51 | $ | .44 | $ | .41 | $ | 1.39 | $ | 1.1 | ||||||||||||||||
| Income (loss) from discontinued operations, net of taxes | — | — | — | — | — | |||||||||||||||||||||
Net income (loss) attributable to Key common shareholders (a) | .51 | .44 | .41 | 1.39 | 1.1 | |||||||||||||||||||||
| Per common share — assuming dilution | ||||||||||||||||||||||||||
| Income (loss) from continuing operations attributable to Key common shareholders | $ | .51 | $ | .44 | $ | .41 | $ | 1.39 | $ | 1.09 | ||||||||||||||||
| Income (loss) from discontinued operations, net of taxes | — | — | — | — | — | |||||||||||||||||||||
Net income (loss) attributable to Key common shareholders (a) | .51 | .44 | $ | .41 | 1.39 | 1.09 | ||||||||||||||||||||
| Cash dividends declared per common share | $ | .205 | $ | .205 | $ | .205 | $ | .615 | $ | .615 | ||||||||||||||||
| Weighted-average common shares outstanding (000) | 1,054,951 | 1,071,229 | 1,100,830 | 1,070,808 | 1,099,520 | |||||||||||||||||||||
Effect of common share options and other stock awards (b) | 9,315 | 8,779 | 9,845 | 9,395 | 8,864 | |||||||||||||||||||||
Weighted-average common shares and potential common shares outstanding (000) (c) | 1,064,266 | 1,080,008 | 1,110,675 | 1,080,203 | 1,108,384 | |||||||||||||||||||||