v3.26.1
REVENUE FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers $ 134 $ 133
Customer-related noninterest income from other sources 38 25
Total customer-related noninterest income 172 158
Noncustomer-related noninterest income 15 13
Total noninterest income 187 171
Commercial account fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 48 45
Card fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 34 34
Retail and business banking fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 20 17
Capital markets fees and income    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 2 10
Wealth management fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 15 14
Other customer-related fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 15 13
Other    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 9 8
Customer-related noninterest income from other sources (2) 4
Total customer-related noninterest income 7 12
Noncustomer-related noninterest income 7 9
Total noninterest income 14 21
Other | Commercial account fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers (1) 0
Other | Card fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 1 0
Other | Retail and business banking fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 0
Other | Capital markets fees and income    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 1 1
Other | Wealth management fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 1
Other | Other customer-related fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 8 6
Zions Bank | Operating Segments    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 40 38
Customer-related noninterest income from other sources 9 4
Total customer-related noninterest income 49 42
Noncustomer-related noninterest income 3 0
Total noninterest income 52 42
Zions Bank | Operating Segments | Commercial account fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 16 15
Zions Bank | Operating Segments | Card fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 12 12
Zions Bank | Operating Segments | Retail and business banking fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 6 5
Zions Bank | Operating Segments | Capital markets fees and income    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 0
Zions Bank | Operating Segments | Wealth management fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 4 4
Zions Bank | Operating Segments | Other customer-related fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 2 2
CB&T | Operating Segments    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 21 18
Customer-related noninterest income from other sources 14 8
Total customer-related noninterest income 35 26
Noncustomer-related noninterest income 3 2
Total noninterest income 38 28
CB&T | Operating Segments | Commercial account fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 8 7
CB&T | Operating Segments | Card fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 4 4
CB&T | Operating Segments | Retail and business banking fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 4 3
CB&T | Operating Segments | Capital markets fees and income    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 1
CB&T | Operating Segments | Wealth management fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 2 1
CB&T | Operating Segments | Other customer-related fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 3 2
Amegy | Operating Segments    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 34 40
Customer-related noninterest income from other sources 11 6
Total customer-related noninterest income 45 46
Noncustomer-related noninterest income 2 2
Total noninterest income 47 48
Amegy | Operating Segments | Commercial account fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 16 15
Amegy | Operating Segments | Card fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 7 7
Amegy | Operating Segments | Retail and business banking fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 4 4
Amegy | Operating Segments | Capital markets fees and income    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 1 8
Amegy | Operating Segments | Wealth management fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 5 5
Amegy | Operating Segments | Other customer-related fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 1 1
NBAZ | Operating Segments    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 10 10
Customer-related noninterest income from other sources 2 0
Total customer-related noninterest income 12 10
Noncustomer-related noninterest income 0 0
Total noninterest income 12 10
NBAZ | Operating Segments | Commercial account fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 3 2
NBAZ | Operating Segments | Card fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 4 4
NBAZ | Operating Segments | Retail and business banking fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 2 2
NBAZ | Operating Segments | Capital markets fees and income    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 0
NBAZ | Operating Segments | Wealth management fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 1 1
NBAZ | Operating Segments | Other customer-related fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 1
NSB | Operating Segments    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 12 11
Customer-related noninterest income from other sources 1 1
Total customer-related noninterest income 13 12
Noncustomer-related noninterest income 0 0
Total noninterest income 13 12
NSB | Operating Segments | Commercial account fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 3 3
NSB | Operating Segments | Card fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 4 4
NSB | Operating Segments | Retail and business banking fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 3 2
NSB | Operating Segments | Capital markets fees and income    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 0
NSB | Operating Segments | Wealth management fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 2 2
NSB | Operating Segments | Other customer-related fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 0
Vectra | Operating Segments    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 7 6
Customer-related noninterest income from other sources 2 2
Total customer-related noninterest income 9 8
Noncustomer-related noninterest income 0 0
Total noninterest income 9 8
Vectra | Operating Segments | Commercial account fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 2 2
Vectra | Operating Segments | Card fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 2 2
Vectra | Operating Segments | Retail and business banking fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 1 1
Vectra | Operating Segments | Capital markets fees and income    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 0
Vectra | Operating Segments | Wealth management fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 1 0
Vectra | Operating Segments | Other customer-related fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 1 1
TCBW | Operating Segments    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 1 2
Customer-related noninterest income from other sources 1 0
Total customer-related noninterest income 2 2
Noncustomer-related noninterest income 0 0
Total noninterest income 2 2
TCBW | Operating Segments | Commercial account fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 1 1
TCBW | Operating Segments | Card fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 1
TCBW | Operating Segments | Retail and business banking fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 0
TCBW | Operating Segments | Capital markets fees and income    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 0
TCBW | Operating Segments | Wealth management fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers 0 0
TCBW | Operating Segments | Other customer-related fees    
Segment Reporting, Revenue Reconciling Item [Line Items]    
Total noninterest income from contracts with customers $ 0 $ 0