Cash Flow (Details) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2025 USD ($)	Dec. 31, 2026 USD ($)	Dec. 31, 2025 USD ($) Plan	Dec. 31, 2024 USD ($)	Dec. 31, 2023 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)			30.00%	31.00%
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)			11.00%	9.00%
Pension Plan [Member] | Alternative investments
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			19.00%	20.00%
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	$ 75		$ 125	$ 100	$ 50
Pension Plan [Member] | SPS [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits	$ 2		3	3
Defined Benefit Plan, Overfunded Plan [Member] | Xcel Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits			$ 13	$ 11	$ 11
Defined Benefit Plan, Overfunded Plan [Member] | Subsequent Event | Xcel Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits		$ 8
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)			25.00%	25.00%
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)			61.00%	61.00%
Other Postretirement Benefits Plan [Member] | Alternative investments
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			13.00%	11.00%
Other Postretirement Benefits Plan [Member] | Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)			1.00%	3.00%
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