Benefit Plans and Other Postretirement Benefits, 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		$ 12	$ 12	$ 11
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Gross Projected Benefit Payments [Abstract]
2022		30
2023		29
2024		29
2025		28
2026		27
2027-2031		123
Expected Medicare Part D Subsidies [Abstract]
2022		2
2023		2
2024		2
2025		2
2026		2
2027-2031		13
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
2020		28
2021		27
2022		27
2023		26
2024		25
2025-2029		110
Pension Plan [Member]
Defined Benefit Plan, Gross Projected Benefit Payments [Abstract]
2022		83
2023		82
2024		82
2025		82
2026		81
2027-2031		388
Pension Plan [Member] | Xcel Energy [Member]
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Total contributions to Xcel Energy's pension plans during the period		131	150	154
Pension Plan [Member] | Xcel Energy [Member] | Subsequent Event
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Total contributions to Xcel Energy's pension plans during the period	$ 50
Pension Plan [Member] | PSCo [Member]
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Total contributions to Xcel Energy's pension plans during the period		46	50	46
Pension Plan [Member] | PSCo [Member] | Subsequent Event
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Total contributions to Xcel Energy's pension plans during the period	40
Defined Benefit Plan, Overfunded Plan [Member] | Xcel Energy [Member]
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Total contributions to Xcel Energy's pension plans during the period		15	11	15
Defined Benefit Plan, Overfunded Plan [Member] | Xcel Energy [Member] | Subsequent Event
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Total contributions to Xcel Energy's pension plans during the period	$ 9
Defined Benefit Plan, Overfunded Plan [Member] | PSCo [Member]
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
Total contributions to Xcel Energy's pension plans during the period		$ 3	$ 3	$ 4