Cash Flow (Details) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) Plan	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
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)		33.00%	35.00%
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)		37.00%	35.00%
Pension Plan [Member] | Short-to-intermediate fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)		11.00%	13.00%
Pension Plan [Member] | Alternative investments
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)		17.00%	15.00%
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		$ 131	$ 150	$ 154
Pension Plan [Member] | SPS [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits		15	14	18
Pension Plan [Member] | Subsequent Event | Xcel Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits	$ 50
Defined Benefit Plan, Overfunded Plan [Member] | Xcel Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits		$ 15	$ 11	$ 15
Defined Benefit Plan, Overfunded Plan [Member] | Subsequent Event | Xcel Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension Benefits	$ 9
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)		15.00%	15.00%
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)		71.00%	72.00%
Other Postretirement Benefits Plan [Member] | Alternative investments
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)		8.00%	9.00%
Other Postretirement Benefits Plan [Member] | Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Target pension asset allocations (as a percent)		6.00%	4.00%
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