v3.26.3
REVENUE FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers $ 138 $ 133 $ 413 $ 396
Customer-related noninterest income from other sources 54 30 133 89
Total customer-related noninterest income 192 163 546 485
Noncustomer-related noninterest income 5 26 298 65
Total noninterest income 197 189 844 550
Commercial account fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 49 47 146 138
Card fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 36 35 106 105
Retail and business banking fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 21 19 61 54
Capital markets fees and income        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 2 4 11 16
Wealth management fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 15 13 43 40
Other customer-related fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 15 15 46 43
Other        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 9 9 29 27
Customer-related noninterest income from other sources 13 (7) 20 (1)
Total customer-related noninterest income 22 2 49 26
Noncustomer-related noninterest income 0 22 275 49
Total noninterest income 22 24 324 75
Other | Commercial account fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 0 1 0
Other | Card fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 1 1 2 2
Other | Retail and business banking fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 (1) (1) (1)
Other | Capital markets fees and income        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 2 2 6 4
Other | Wealth management fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 (2) 0 2
Other | Other customer-related fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 6 9 21 20
Zions Bank | Operating Segments        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 42 39 123 116
Customer-related noninterest income from other sources 14 10 30 23
Total customer-related noninterest income 56 49 153 139
Noncustomer-related noninterest income 1 0 3 2
Total noninterest income 57 49 156 141
Zions Bank | Operating Segments | Commercial account fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 17 15 49 45
Zions Bank | Operating Segments | Card fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 13 12 37 37
Zions Bank | Operating Segments | Retail and business banking fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 6 6 18 16
Zions Bank | Operating Segments | Capital markets fees and income        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 0 1 0
Zions Bank | Operating Segments | Wealth management fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 4 4 12 12
Zions Bank | Operating Segments | Other customer-related fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 2 2 6 6
CB&T | Operating Segments        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 21 21 63 59
Customer-related noninterest income from other sources 11 9 37 28
Total customer-related noninterest income 32 30 100 87
Noncustomer-related noninterest income 1 1 9 4
Total noninterest income 33 31 109 91
CB&T | Operating Segments | Commercial account fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 8 8 25 24
CB&T | Operating Segments | Card fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 4 4 13 13
CB&T | Operating Segments | Retail and business banking fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 4 4 11 10
CB&T | Operating Segments | Capital markets fees and income        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 1 1 2
CB&T | Operating Segments | Wealth management fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 2 2 5 4
CB&T | Operating Segments | Other customer-related fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 3 2 8 6
Amegy | Operating Segments        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 35 33 104 105
Customer-related noninterest income from other sources 12 13 33 27
Total customer-related noninterest income 47 46 137 132
Noncustomer-related noninterest income 3 3 10 8
Total noninterest income 50 49 147 140
Amegy | Operating Segments | Commercial account fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 16 15 47 46
Amegy | Operating Segments | Card fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 8 8 22 22
Amegy | Operating Segments | Retail and business banking fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 5 4 13 11
Amegy | Operating Segments | Capital markets fees and income        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 0 3 9
Amegy | Operating Segments | Wealth management fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 5 5 15 13
Amegy | Operating Segments | Other customer-related fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 1 1 4 4
NBAZ | Operating Segments        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 10 10 32 29
Customer-related noninterest income from other sources 2 2 5 3
Total customer-related noninterest income 12 12 37 32
Noncustomer-related noninterest income 0 0 1 (1)
Total noninterest income 12 12 38 31
NBAZ | Operating Segments | Commercial account fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 3 3 8 7
NBAZ | Operating Segments | Card fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 4 4 12 11
NBAZ | Operating Segments | Retail and business banking fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 2 2 8 7
NBAZ | Operating Segments | Capital markets fees and income        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 0 0 0
NBAZ | Operating Segments | Wealth management fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 1 1 3 3
NBAZ | Operating Segments | Other customer-related fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 0 1 1
NSB | Operating Segments        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 12 12 36 35
Customer-related noninterest income from other sources 1 1 3 3
Total customer-related noninterest income 13 13 39 38
Noncustomer-related noninterest income 0 0 0 0
Total noninterest income 13 13 39 38
NSB | Operating Segments | Commercial account fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 3 3 9 9
NSB | Operating Segments | Card fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 4 4 12 12
NSB | Operating Segments | Retail and business banking fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 3 3 9 8
NSB | Operating Segments | Capital markets fees and income        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 0 0 0
NSB | Operating Segments | Wealth management fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 2 2 6 5
NSB | Operating Segments | Other customer-related fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 0 0 1
Vectra | Operating Segments        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 8 8 22 21
Customer-related noninterest income from other sources 1 1 3 4
Total customer-related noninterest income 9 9 25 25
Noncustomer-related noninterest income 0 0 0 3
Total noninterest income 9 9 25 28
Vectra | Operating Segments | Commercial account fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 2 2 6 5
Vectra | Operating Segments | Card fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 2 2 7 7
Vectra | Operating Segments | Retail and business banking fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 1 1 3 3
Vectra | Operating Segments | Capital markets fees and income        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 1 0 1
Vectra | Operating Segments | Wealth management fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 1 1 2 1
Vectra | Operating Segments | Other customer-related fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 2 1 4 4
TCBNW | Operating Segments        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 1 1 4 4
Customer-related noninterest income from other sources 0 1 2 2
Total customer-related noninterest income 1 2 6 6
Noncustomer-related noninterest income 0 0 0 0
Total noninterest income 1 2 6 6
TCBNW | Operating Segments | Commercial account fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 1 1 2
TCBNW | Operating Segments | Card fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 0 1 1
TCBNW | Operating Segments | Retail and business banking fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 0 0 0
TCBNW | Operating Segments | Capital markets fees and income        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 0 0 0
TCBNW | Operating Segments | Wealth management fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers 0 0 0 0
TCBNW | Operating Segments | Other customer-related fees        
Segment Reporting [Line Items]        
Total noninterest income from contracts with customers $ 1 $ 0 $ 2 $ 1