Borrowings and Other Financing Instruments Long-Term Borrowings (Details) - Bonds [Member] - USD ($)	Jul. 15, 2022	Jun. 30, 2022
PSCo | Series Due June 1, 2032
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 300,000,000
Debt Instrument, Interest Rate, Stated Percentage		4.10%
PSCo | Series Due June 1, 2052
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 400,000,000
Debt Instrument, Interest Rate, Stated Percentage		4.50%
SPS | Series Due June 1, 2052
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 200,000,000
Debt Instrument, Interest Rate, Stated Percentage		5.15%
NSP-Wisconsin | Series Due September 15, 2052 | Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 100,000,000
Debt Instrument, Interest Rate, Stated Percentage	4.86%
NSP-Minnesota | Series Due June 1, 2052
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 500,000,000
Debt Instrument, Interest Rate, Stated Percentage		4.50%
XCEL ENERGY INC [Member] | Series Due June 1, 2032
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 700,000,000
Debt Instrument, Interest Rate, Stated Percentage		4.60%