Borrowings and Other Financing Instruments Debt Repurchase (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025
NSP-Minnesota
Debt Disclosure [Abstract]
Debt Instrument, Repurchased Face Amount	$ 89	$ 128
Debt Instrument, Repurchase Amount	59	81
Debt Repurchase [Line Items]
Debt Instrument, Repurchased Face Amount	89	128
Debt Instrument, Repurchase Amount	59	81
SPS
Debt Disclosure [Abstract]
Debt Instrument, Repurchased Face Amount	4
Debt Instrument, Repurchase Amount	3
Debt Repurchase [Line Items]
Debt Instrument, Repurchased Face Amount	4
Debt Instrument, Repurchase Amount	3
XCEL ENERGY INC [Member]
Debt Disclosure [Abstract]
Gain (Loss) on Repurchase of Debt Instrument	29	43
Debt Repurchase [Line Items]
Gain (Loss) on Repurchase of Debt Instrument	$ 29	$ 43
Series due March 1, 2050 \| Bonds [Member] \| NSP-Minnesota
Debt Disclosure [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	2.90%
Debt Repurchase [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.90%
Series Due June 1, 2051 [Domain] \| Bonds [Member] \| NSP-Minnesota
Debt Disclosure [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	2.60%
Debt Repurchase [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.60%
Series due April 1, 2052 \| Bonds [Member] \| NSP-Minnesota
Debt Disclosure [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	3.20%
Debt Repurchase [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.20%
Series Due Sept. 15, 2047 \| Bonds [Member] \| NSP-Minnesota
Debt Disclosure [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	3.60%
Debt Repurchase [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.60%
Series Due Aug. 15, 2047 \| Bonds [Member] \| SPS
Debt Disclosure [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	3.70%
Debt Repurchase [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.70%
Series Due Nov. 15, 2048 \| Bonds [Member] \| SPS
Debt Disclosure [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	4.40%
Debt Repurchase [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.40%
Series Due June 15, 2049 \| Bonds [Member] \| SPS
Debt Disclosure [Abstract]
Debt Instrument, Interest Rate, Stated Percentage	3.75%
Debt Repurchase [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.75%