Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating expenses
Interest Expense, Related Party	$ 1	$ 0	$ 0
Accounts Receivable and Payable with Affiliates [Abstract]
Accounts receivable	8	3
Accounts payable	19	23
NSP-Minnesota
Accounts Receivable and Payable with Affiliates [Abstract]
Accounts receivable	0	0
Accounts payable	4	13
PSCo
Accounts Receivable and Payable with Affiliates [Abstract]
Accounts receivable	2	2
Accounts payable	0	0
Other subsidiaries of Xcel Energy Inc.
Accounts Receivable and Payable with Affiliates [Abstract]
Accounts receivable	6	1
Accounts payable	15	10
Purchased Power
Operating expenses
Costs and Expenses, Related Party	445	408	379
Transmission Expense
Operating expenses
Costs and Expenses, Related Party	68	64	61
Natural Gas Purchase for Resale
Operating expenses
Costs and Expenses, Related Party	0	1	1
Other Expense
Operating expenses
Costs and Expenses, Related Party	114	99	92
Electricity, US Regulated
Operating revenues
Revenue from Related Parties	$ 202	$ 189	$ 168