v3.25.4
OPERATING SEGMENT INFORMATION (Schedule Of Segment Information) (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2025
Sep. 30, 2025
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Sep. 30, 2024
Jun. 30, 2024
Mar. 31, 2024
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Segment Reporting Information [Line Items]                      
Net interest income $ 683 $ 672 $ 648 $ 624 $ 627 $ 620 $ 597 $ 586 $ 2,627 $ 2,430 $ 2,438
Provision for credit losses 6 49 (1) 18 41 13 5 13 72 72 132
Net interest income after provision for credit losses                 2,555 2,358 2,306
Noninterest income                 758 700 677
Salaries and employee benefits                 1,350 1,287 1,275
Technology, telecom, and information processing                 276 260 240
Occupancy and equipment, net                 166 161 160
Other direct expenses                 346 338 422
Indirect/allocated expenses                 0 0 0
Total noninterest expense 546 527 527 538 509 502 509 526 2,138 2,046 2,097
Income (loss) before taxes $ 339 $ 285 $ 312 $ 239 $ 270 $ 277 $ 262 $ 203 1,175 1,012 886
Total average loans                 60,421 58,547 56,740
Total average deposits                 74,873 74,760 72,866
Other                      
Segment Reporting Information [Line Items]                      
Net interest income                 (12) 5 28
Provision for credit losses                 1 (2) (2)
Net interest income after provision for credit losses                 (13) 7 30
Noninterest income                 113 85 65
Salaries and employee benefits                 818 755 746
Technology, telecom, and information processing                 232 219 197
Occupancy and equipment, net                 34 32 35
Other direct expenses                 135 103 117
Indirect/allocated expenses                 (1,091) (1,036) (988)
Total noninterest expense                 128 73 107
Income (loss) before taxes                 (28) 19 (12)
Total average loans                 903 958 1,046
Total average deposits                 4,983 5,484 6,161
Zions Bank | Operating Segments                      
Segment Reporting Information [Line Items]                      
Net interest income                 738 692 698
Provision for credit losses                 14 (8) 20
Net interest income after provision for credit losses                 724 700 678
Noninterest income                 190 187 192
Salaries and employee benefits                 140 141 142
Technology, telecom, and information processing                 16 14 16
Occupancy and equipment, net                 28 27 27
Other direct expenses                 58 71 96
Indirect/allocated expenses                 328 318 301
Total noninterest expense                 570 571 582
Income (loss) before taxes                 344 316 288
Total average loans                 15,035 14,799 14,296
Total average deposits                 21,151 21,151 20,233
CB&T | Operating Segments                      
Segment Reporting Information [Line Items]                      
Net interest income                 647 584 602
Provision for credit losses                 53 42 44
Net interest income after provision for credit losses                 594 542 558
Noninterest income                 126 121 116
Salaries and employee benefits                 130 126 126
Technology, telecom, and information processing                 5 5 5
Occupancy and equipment, net                 35 33 34
Other direct expenses                 44 42 58
Indirect/allocated expenses                 219 197 188
Total noninterest expense                 433 403 411
Income (loss) before taxes                 287 260 263
Total average loans                 15,098 14,286 14,128
Total average deposits                 15,334 14,582 14,253
Amegy | Operating Segments                      
Segment Reporting Information [Line Items]                      
Net interest income                 565 496 457
Provision for credit losses                 8 22 15
Net interest income after provision for credit losses                 557 474 442
Noninterest income                 189 175 184
Salaries and employee benefits                 112 112 107
Technology, telecom, and information processing                 8 8 8
Occupancy and equipment, net                 33 33 28
Other direct expenses                 50 56 70
Indirect/allocated expenses                 262 247 240
Total noninterest expense                 465 456 453
Income (loss) before taxes                 281 193 173
Total average loans                 14,220 13,398 12,851
Total average deposits                 14,777 14,792 13,569
NBAZ | Operating Segments                      
Segment Reporting Information [Line Items]                      
Net interest income                 262 245 249
Provision for credit losses                 (14) 17 4
Net interest income after provision for credit losses                 276 228 245
Noninterest income                 44 43 40
Salaries and employee benefits                 53 54 55
Technology, telecom, and information processing                 4 4 4
Occupancy and equipment, net                 10 11 10
Other direct expenses                 24 26 29
Indirect/allocated expenses                 104 101 96
Total noninterest expense                 195 196 194
Income (loss) before taxes                 125 75 91
Total average loans                 5,596 5,683 5,318
Total average deposits                 6,915 6,933 7,008
NSB | Operating Segments                      
Segment Reporting Information [Line Items]                      
Net interest income                 213 197 192
Provision for credit losses                 (2) (11) 42
Net interest income after provision for credit losses                 215 208 150
Noninterest income                 52 52 45
Salaries and employee benefits                 44 46 45
Technology, telecom, and information processing                 6 6 5
Occupancy and equipment, net                 11 11 12
Other direct expenses                 18 21 27
Indirect/allocated expenses                 95 93 85
Total noninterest expense                 174 177 174
Income (loss) before taxes                 93 83 21
Total average loans                 3,718 3,555 3,392
Total average deposits                 7,141 7,169 6,964
Vectra | Operating Segments                      
Segment Reporting Information [Line Items]                      
Net interest income                 143 148 151
Provision for credit losses                 9 3 7
Net interest income after provision for credit losses                 134 145 144
Noninterest income                 36 29 28
Salaries and employee benefits                 40 41 41
Technology, telecom, and information processing                 3 2 3
Occupancy and equipment, net                 12 11 12
Other direct expenses                 13 14 18
Indirect/allocated expenses                 69 69 67
Total noninterest expense                 137 137 141
Income (loss) before taxes                 33 37 31
Total average loans                 3,846 4,063 4,004
Total average deposits                 3,417 3,505 3,482
TCBW | Operating Segments                      
Segment Reporting Information [Line Items]                      
Net interest income                 71 63 61
Provision for credit losses                 3 9 2
Net interest income after provision for credit losses                 68 54 59
Noninterest income                 8 8 7
Salaries and employee benefits                 13 12 13
Technology, telecom, and information processing                 2 2 2
Occupancy and equipment, net                 3 3 2
Other direct expenses                 4 5 7
Indirect/allocated expenses                 14 11 11
Total noninterest expense                 36 33 35
Income (loss) before taxes                 40 29 31
Total average loans                 2,005 1,805 1,705
Total average deposits                 $ 1,155 $ 1,144 $ 1,196