Benefit Plans and Other Postretirement Benefits (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended			9 Months Ended
		Jan. 31, 2023	Sep. 30, 2023	Sep. 30, 2022		Sep. 30, 2023		Sep. 30, 2022
Components of Net Periodic Benefit Cost [Abstract]
Operating and maintenance expenses			$ 586	$ 611		$ 1,864		$ 1,827
Pension Plan [Member]
Components of Net Periodic Benefit Cost [Abstract]
Service cost			18	24		55		73
Interest Cost	[1]		39	28		119		83
Expected Return on Plan Assets	[1]		(52)	(52)		(157)		(156)
Amortization of Prior Service Credit	[1]		0	0		(1)		(1)
Amortization of Net Loss	[1]		6	19		17		56
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement			0	55	[2]	0	[2]	54	[2]
Net periodic benefit cost (credit)			11	74		33		109
Effects of regulation			11	(37)		25		(30)
Net benefit cost (credit) recognized for financial reporting			22	37		58		79
Operating and maintenance expenses						7
Pension Plan [Member] | Parent Company
Components of Net Periodic Benefit Cost [Abstract]
Contributions to Xcel Energy's pension plans		$ 50
Other Postretirement Benefits Plan [Member]
Components of Net Periodic Benefit Cost [Abstract]
Service cost			0	0		1		1
Interest Cost	[1]		6	3		17		11
Expected Return on Plan Assets	[1]		(4)	(4)		(13)		(13)
Amortization of Prior Service Credit	[1]		0	(2)		(1)		(5)
Amortization of Net Loss	[1]		0	1		1		2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement			0	0		0	[2]	0	[2]
Net periodic benefit cost (credit)			2	(2)		5		(4)
Effects of regulation			0	1		0		2
Net benefit cost (credit) recognized for financial reporting			$ 2	$ (1)		$ 5		$ (2)

[1] The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset

[2] A settlement charge is required when the amount of lump-sum distributions during the year is greater than the sum of the service and interest cost components of the annual net periodic pension cost. In the third quarter of 2022, as a result of lump-sum distributions during the 2022 plan year, Xcel Energy recorded a pension settlement charge of $55 million, the majority of which were not recognized in earnings due to the effects of regulation. A total of $7 million of those amounts were recorded in other expense in the third quarter of 2022.