Cash Flow (Details) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($) Plan	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			100.00%	100.00%
Pension Plan [Member] | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			31.00%	33.00%
Pension Plan [Member] | Long-Duration Fixed Income and Long-duration fixed income and interest rate swap securities
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			38.00%	38.00%
Pension Plan [Member] | Short-to-intermediate fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			9.00%	9.00%
Pension Plan [Member] | Alternative investments
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			20.00%	18.00%
Pension Plan [Member] | Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			2.00%	2.00%
Pension Plan [Member] | Xcel Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits			$ 50	$ 50	$ 131
Pension Plan [Member] | SPS [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits					15
Pension Plan [Member] | Subsequent Event | Xcel Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits	$ 100
Defined Benefit Plan, Overfunded Plan [Member] | Xcel Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits			$ 11	$ 13	$ 15
Defined Benefit Plan, Overfunded Plan [Member] | Subsequent Event | Xcel Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits		$ 11
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			100.00%	100.00%
Other Postretirement Benefits Plan [Member] | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			9.00%	16.00%
Other Postretirement Benefits Plan [Member] | Long-Duration Fixed Income and Long-duration fixed income and interest rate swap securities
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			0.00%	0.00%
Other Postretirement Benefits Plan [Member] | Short-to-intermediate fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			77.00%	71.00%
Other Postretirement Benefits Plan [Member] | Alternative investments
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			13.00%	12.00%
Other Postretirement Benefits Plan [Member] | Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			1.00%	1.00%
Parent Company [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan number of pension plans to which contributions were made | Plan			4