v3.26.1
Employee Benefit Plan, Fair Value and NAV Practical Expedient (Details) - EPB 012 [Member] - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value $ 3,571 $ 3,165
Regions Stock Fund    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 340 320
Mutual Fund    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 1,024 899
Common Collective Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 2,207 1,946
Total Asset in the fair value hierarchy    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 1,364 1,219
Fair Value, Inputs, Level 1 | Regions Stock Fund    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 340 320
Fair Value, Inputs, Level 1 | Mutual Fund    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 1,024 899
Fair Value, Inputs, Level 1 | Total Asset in the fair value hierarchy    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 1,364 1,219
Fair Value Measured at Net Asset Value Per Share    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 2,207 1,946
Fair Value Measured at Net Asset Value Per Share | Morley Stable Value Fund    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 238 254
Fair Value Measured at Net Asset Value Per Share | Pioneer Large Cap Core Equity Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 153 132
Fair Value Measured at Net Asset Value Per Share | Pioneer US Balanced Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 142 136
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirement 2005 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 4 3
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirement 2010 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 2 2
Fair Value Measured at Net Asset Value Per Share | T. Rowe Retirement 2015 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 7 8
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirement 2020 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 26 24
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirement 2025 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 75 72
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirement 2030 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 123 109
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirement 2035 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 169 135
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirement 2040 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 165 132
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirement 2045 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 173 135
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirement 2050 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 143 112
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirment 2055 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 105 83
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirement 2060 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 65 49
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Retirement 2065 Trust    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 18 11
Fair Value Measured at Net Asset Value Per Share | T. Rowe Price Large Cap Growth    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 396 357
Fair Value Measured at Net Asset Value Per Share | BNYM EB US Sa=mall-Mid Cap Growth Equity Fund    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 108 102
Fair Value Measured at Net Asset Value Per Share | Victory Integrity Small/Mid Cap Value    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value 89 89
Fair Value Measured at Net Asset Value Per Share | Harding Loevner International Equity    
Employee Benefit Plan, Investment, Fair Value and NAV [Line Items]    
Employee Benefit Plan, Investment, Excluding Plan Interest in Master Trust, Fair Value $ 6 $ 1