Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accounts Receivable and Payable with Affiliates [Abstract]
Accounts receivable	$ 11	$ 13
Accounts payable	75	69
Interest expense	2	0	$ 0
NSP-Minnesota
Accounts Receivable and Payable with Affiliates [Abstract]
Accounts receivable	2	0
Accounts payable	0	16
NSP-Wisconsin
Accounts Receivable and Payable with Affiliates [Abstract]
Accounts receivable	0	0
Accounts payable	2	2
SPS
Accounts Receivable and Payable with Affiliates [Abstract]
Accounts receivable	0	0
Accounts payable	11	7
Other subsidiaries of Xcel Energy Inc.
Accounts Receivable and Payable with Affiliates [Abstract]
Accounts receivable	9	13
Accounts payable	62	44
Other Expense
Operating expenses
Costs and Expenses, Related Party	670	617	571
Other Revenue
Operating revenues
Operating Revenue from Related Parties	$ 5	$ 5	$ 5