v3.26.1
SEGMENT INFORMATION - Significant Segment Expenses and Measure of Segment Profit or Loss (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Segment Reporting [Line Items]          
Net interest income (expense) $ 1,656 $ 1,695 $ 3,277 $ 3,358  
Rental income on operating lease equipment 280 272 561 542  
All other noninterest income 496 406 907 771  
Total noninterest income 776 678 1,468 1,313  
Total revenue 2,432 2,373 4,745 4,671  
Depreciation on operating lease equipment 101 100 202 198  
Maintenance and other operating lease expenses 67 55 132 113  
Personnel cost 844 810 1,713 1,628  
Acquisition-related expenses 8 38 13 80  
All other noninterest expense 531 497 1,027 974  
Total noninterest expense 1,551 1,500 3,087 2,993  
Provision (benefit) for credit losses (10) 115 62 269  
Income (loss) before income taxes 891 758 1,596 1,409  
Income tax expense (benefit) 219 183 390 351  
Net income (loss) 672 575 1,206 1,058  
Loans and leases 151,034 141,269 151,034 141,269 $ 147,930
Operating lease equipment, net 9,755 9,466 9,755 9,466 9,621
Investment securities 43,557 43,346 43,557 43,346  
Deposits 173,427 159,935 173,427 159,935 $ 161,578
Operating Segments | General Bank          
Segment Reporting [Line Items]          
Net interest income (expense) 819 824 1,632 1,612  
Rental income on operating lease equipment 0 0 0 0  
All other noninterest income 187 164 359 328  
Total noninterest income 187 164 359 328  
Total revenue 1,006 988 1,991 1,940  
Depreciation on operating lease equipment 0 0 0 0  
Maintenance and other operating lease expenses 0 0 0 0  
Personnel cost 209 207 424 417  
Acquisition-related expenses 0 0 0 0  
All other noninterest expense 392 373 777 728  
Total noninterest expense 601 580 1,201 1,145  
Provision (benefit) for credit losses 54 13 71 59  
Income (loss) before income taxes 351 395 719 736  
Income tax expense (benefit) 85 101 175 189  
Net income (loss) 266 294 544 547  
Loans and leases 64,355 64,987 64,355 64,987  
Operating lease equipment, net 0 0 0 0  
Investment securities 18 0 18 0  
Deposits 75,718 73,499 75,718 73,499  
Operating Segments | Commercial Bank          
Segment Reporting [Line Items]          
Net interest income (expense) 805 789 1,607 1,575  
Rental income on operating lease equipment 54 54 109 110  
All other noninterest income 270 228 500 429  
Total noninterest income 324 282 609 539  
Total revenue 1,129 1,071 2,216 2,114  
Depreciation on operating lease equipment 43 44 86 88  
Maintenance and other operating lease expenses 0 0 0 0  
Personnel cost 186 183 385 373  
Acquisition-related expenses 0 0 0 0  
All other noninterest expense 400 422 804 842  
Total noninterest expense 629 649 1,275 1,303  
Provision (benefit) for credit losses (64) 102 (9) 210  
Income (loss) before income taxes 564 320 950 601  
Income tax expense (benefit) 136 82 231 154  
Net income (loss) 428 238 719 447  
Loans and leases 86,635 76,220 86,635 76,220  
Operating lease equipment, net 723 750 723 750  
Investment securities 0 0 0 0  
Deposits 45,690 40,697 45,690 40,697  
Operating Segments | Rail          
Segment Reporting [Line Items]          
Net interest income (expense) (59) (53) (117) (105)  
Rental income on operating lease equipment 226 218 452 432  
All other noninterest income 7 3 16 5  
Total noninterest income 233 221 468 437  
Total revenue 174 168 351 332  
Depreciation on operating lease equipment 58 56 116 110  
Maintenance and other operating lease expenses 67 55 132 113  
Personnel cost 6 6 14 14  
Acquisition-related expenses 0 0 0 0  
All other noninterest expense 18 26 35 40  
Total noninterest expense 149 143 297 277  
Provision (benefit) for credit losses 0 0 0 0  
Income (loss) before income taxes 25 25 54 55  
Income tax expense (benefit) 6 6 13 14  
Net income (loss) 19 19 41 41  
Loans and leases 44 62 44 62  
Operating lease equipment, net 9,032 8,716 9,032 8,716  
Investment securities 0 0 0 0  
Deposits 2 3 2 3  
Corporate          
Segment Reporting [Line Items]          
Net interest income (expense) 91 135 155 276  
Rental income on operating lease equipment 0 0 0 0  
All other noninterest income 32 11 32 9  
Total noninterest income 32 11 32 9  
Total revenue 123 146 187 285  
Depreciation on operating lease equipment 0 0 0 0  
Maintenance and other operating lease expenses 0 0 0 0  
Personnel cost 443 414 890 824  
Acquisition-related expenses 8 38 13 80  
All other noninterest expense (279) (324) (589) (636)  
Total noninterest expense 172 128 314 268  
Provision (benefit) for credit losses 0 0 0 0  
Income (loss) before income taxes (49) 18 (127) 17  
Income tax expense (benefit) (8) (6) (29) (6)  
Net income (loss) (41) 24 (98) 23  
Loans and leases 0 0 0 0  
Operating lease equipment, net 0 0 0 0  
Investment securities 43,539 43,346 43,539 43,346  
Deposits $ 52,017 $ 45,736 $ 52,017 $ 45,736