v3.26.1
Employee Benefit Plan, Schedule, Asset Held for Investment (Details) - XCEL 401(k) - USD ($)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] $ 3,287,987,220  
EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution $ 17,903,047  
Minimum    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Participant Loan, Interest Rate 4.25% 4.25%
Vanguard Institutional 500 Index Trust    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] $ 684,381,801  
Vanguard Mid-Cap Index Fund Institutional Plus Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 239,128,271  
Vanguard PRIMECAP Fund Admiral Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 278,886,587  
Vanguard Institutional Total Bond Market Index Trust    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 210,656,983  
Vanguard Developed Market Index Institutional Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 212,086,744  
Vanguard Small Cap Index Fund Institutional Plus Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 123,897,001  
Vanguard Target Retirement 2045 Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 163,450,120  
Vanguard Federal Money Market    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 118,063,480  
Vanguard Target Retirement 2050 Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 154,152,015  
Vanguard Target Retirement 2030 Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 145,541,141  
Vanguard Target Retirement 2035 Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 151,244,349  
Vanguard Target Retirement 2040 Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 137,895,500  
Self-Directed Brokerage Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 103,624,911  
BlackRock Total Return Bond Fund; Class M    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 92,386,594  
Vanguard Target Retirement 2055 Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 89,891,538  
Vanguard Emerging Markets Stock Index Fund Institutional Shares    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 70,370,986  
Vanguard Target Retirement 2020 Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 52,343,489  
Vanguard Target Retirement 2060 Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 53,994,007  
Vanguard Target Retirement Income Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 45,463,385  
Vanguard Target Retirement 2065 Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 19,224,222  
Vanguard Institutional Extended Market Index Trust    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 11,605,665  
Vanguard Target Retirement 2070 Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 3,828,616  
Vanguard Target Retirement Income and Growth Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] 1,543,617  
Vanguard Target Retirement 2025 Trust Plus    
EBP, Schedule of Asset Held for Investment [Line Items]    
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] $ 106,423,151