Regulatory Plant Decommissioning Recovery (Details) - USD ($) $ in Millions	Dec. 31, 2024		Dec. 31, 2023		Dec. 31, 2022
Regulatory Basis to GAAP Basis Reconciliation [Abstract]
Asset Retirement Obligation	$ 3,713		$ 3,218		$ 3,380
Nuclear Plant [Member]
Regulatory Basis to GAAP Basis Reconciliation [Abstract]
Asset Retirement Obligation	2,476		2,107		$ 2,160
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member]
Funded Status of Nuclear Decommissioning Obligation [Abstract]
Decommissioning fund investments	$ 3,494	[1]	3,211	[2]
NSP Minnesota
Regulatory Plant Decommissioning Recovery [Abstract]
Percentage Of Total Obligation For Decommissioning Expected To Be Funded By External Funds	100.00%
NSP Minnesota | Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member]
Funded Status of Nuclear Decommissioning Obligation [Abstract]
Decommissioning fund investments	$ 3,500		$ 3,200

[1] Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $246 million of equity method investments and $156 million of rabbi trust assets and other miscellaneous investments.

[2] Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $244 million of equity investments in unconsolidated subsidiaries and $144 million of rabbi trust assets and other miscellaneous investments.