Benefit Plans and Other Postretirement Benefits, Postretirement Health Care Benefits (Details) - Employees	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Voluntary Retirement Program \| Xcel Energy [Member]
Postretirement Health Care Benefits [Abstract]
Entity Number of Employees			400
Employee Severance \| Xcel Energy [Member]
Postretirement Health Care Benefits [Abstract]
Entity Number of Employees			150
Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	100.00%	100.00%
Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	100.00%	100.00%
Domestic and international equity securities \| Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	25.00%	25.00%
Domestic and international equity securities \| Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	30.00%	31.00%
Short-to-intermediate fixed income securities \| Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	61.00%	61.00%
Short-to-intermediate fixed income securities \| Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	11.00%	9.00%
Alternative investments \| Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	13.00%	11.00%
Alternative investments \| Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	19.00%	20.00%
Cash \| Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	1.00%	3.00%
Cash \| Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	2.00%	2.00%
Long-duration fixed income and interest rate swap securities \| Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.00%	0.00%
Long-duration fixed income and interest rate swap securities \| Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	38.00%	38.00%

NORTHERN STATES POWER CO /WI/ 10-K