Benefit Plans and Other Postretirement Benefits (Details) - Pension Plan [Member] - USD ($) $ in Millions		1 Months Ended	3 Months Ended
		Jan. 31, 2024	Mar. 31, 2024	Mar. 31, 2023
Components of Net Periodic Benefit Cost (Credit) [Abstract]
Service cost			$ 2	$ 2
Interest cost (a)	[1]		5	6
Expected return on plan assets (a)	[1]		(8)	(8)
Amortization of net loss (gain) (a)	[1]		1	0
Net periodic benefit cost (credit)			0	0
Contributions to pension plans		$ 3
Defined Benefit Plan Credits Not Recognized Due To Effects of Regulation			1	1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)			$ 1	$ 1
Xcel Energy Inc.
Components of Net Periodic Benefit Cost (Credit) [Abstract]
Contributions to pension plans		$ 100

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