Income Taxes (Details)		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Federal statutory rate, percent		21.00%	21.00%
State tax (net of federal tax effect), percent		2.50%	2.60%
Wind PTCs, percent	[1]	(55.80%)	(61.60%)
Plant regulatory differences, percent	[2]	(4.00%)	(5.00%)
Other tax credits, percent		(1.10%)	(1.20%)
Other (net), percent		0.60%	(0.60%)
Effective income tax rate, percent		(36.80%)	(44.80%)

[1] Wind PTCs are credited to customers (reduction to revenue) and do not materially impact net income.

[2] Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.