Borrowings and Other Financing Instruments Revolving Credit Facilities (Details) - Revolving Credit Facility [Member] - USD ($) $ in Millions		Mar. 31, 2024	Dec. 31, 2023
Line of Credit Facility [Line Items]
Credit Facility	[1]	$ 3,550
Outstanding	[2]	508
Available		3,042
Direct advances on the credit facility outstanding		0	$ 0
PSCo
Line of Credit Facility [Line Items]
Credit Facility	[1]	700
Outstanding	[2]	298
Available		402
NSP-Minnesota
Line of Credit Facility [Line Items]
Credit Facility	[1]	700
Outstanding	[2]	15
Available		685
SPS
Line of Credit Facility [Line Items]
Credit Facility	[1]	500
Outstanding	[2]	145
Available		355
NSP-Wisconsin
Line of Credit Facility [Line Items]
Credit Facility	[1]	150
Outstanding	[2]	0
Available		150
Xcel Energy Inc.
Line of Credit Facility [Line Items]
Credit Facility	[1]	1,500
Outstanding	[2]	50
Available		$ 1,450

[1] Expires in September 2027.

[2] Includes outstanding commercial paper and letters of credit.