Borrowings and Other Financing Instruments Long-Term Borrowings (Details) $ in Millions	3 Months Ended
	Jun. 30, 2026 USD ($)
Forward Contract Indexed to Issuer's Equity [Line Items]
2025 ATM Program Total Available Proceeds	$ 4,000
Series Due March 13, 2029 \| Bonds [Member] \| PSCo
Forward Contract Indexed to Issuer's Equity [Line Items]
Debt Instrument, Face Amount	$ 700
Debt Instrument, Interest Rate, Stated Percentage	4.15%
Series Due June 15, 2036 \| Bonds [Member] \| PSCo
Forward Contract Indexed to Issuer's Equity [Line Items]
Debt Instrument, Face Amount	$ 600
Debt Instrument, Interest Rate, Stated Percentage	5.05%
Series Due June 15, 2041 \| Bonds [Member] \| NSP-Wisconsin
Forward Contract Indexed to Issuer's Equity [Line Items]
Debt Instrument, Face Amount	$ 250
Debt Instrument, Interest Rate, Stated Percentage	5.48%
Series due May 15, 2036 \| Bonds [Member] \| NSP-Minnesota
Forward Contract Indexed to Issuer's Equity [Line Items]
Debt Instrument, Face Amount	$ 600
Debt Instrument, Interest Rate, Stated Percentage	4.85%
Series due May 15, 2056 \| Bonds [Member] \| NSP-Minnesota
Forward Contract Indexed to Issuer's Equity [Line Items]
Debt Instrument, Face Amount	$ 600
Debt Instrument, Interest Rate, Stated Percentage	5.55%
364-Day Term Loan \| Xcel Energy Inc. \| Short-Term Debt
Forward Contract Indexed to Issuer's Equity [Line Items]
Credit Facility	$ 1,500
Series Due 2056 [Member] \| Bonds [Member] \| XCEL ENERGY INC [Member]
Forward Contract Indexed to Issuer's Equity [Line Items]
Debt Instrument, Face Amount	$ 800
Debt Instrument, Interest Rate, Stated Percentage	5.75%
Series due August 15, 2036 \| Bonds [Member] \| SPS
Forward Contract Indexed to Issuer's Equity [Line Items]
Debt Instrument, Face Amount	$ 650
Debt Instrument, Interest Rate, Stated Percentage	5.30%
Series due August 15, 2056 \| Bonds [Member] \| SPS
Forward Contract Indexed to Issuer's Equity [Line Items]
Debt Instrument, Face Amount	$ 550
Debt Instrument, Interest Rate, Stated Percentage	5.875%