Projected Benefit Payments (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Defined Contribution Plan, Administrative Expense		$ 3	$ 3	$ 3
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Accumulated Benefit Obligation		506	519
Defined Benefit Plan, Gross Projected Benefit Payments [Abstract]
2022		33
2023		31
2024		31
2025		32
2026		31
2027-2031		153
Pension Plan [Member] | Xcel Energy [Member]
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Payment for Pension Benefits		131	150	154
Pension Plan [Member] | Xcel Energy [Member] | Subsequent Event
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Payment for Pension Benefits	$ 50
Pension Plan [Member] | SPS [Member]
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Payment for Pension Benefits		15	14	18
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Gross Projected Benefit Payments [Abstract]
2022		3
2023		2
2024		2
2025		2
2026		2
2027-2031		11
Expected Medicare Part D Subsidies [Abstract]
2022		0
2023		0
2024		0
2025		0
2026		0
2027-2031		0
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
2022		3
2023		2
2024		2
2025		2
2026		2
2027-2031		11
Defined Benefit Plan, Overfunded Plan [Member] | Xcel Energy [Member]
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Payment for Pension Benefits		$ 15	$ 11	$ 15
Defined Benefit Plan, Overfunded Plan [Member] | Xcel Energy [Member] | Subsequent Event
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Payment for Pension Benefits	$ 9