Acquisitions - Tatanka Ridge (Details) $ in Millions	1 Months Ended
	Dec. 31, 2020 USD ($) MW	Dec. 31, 2021 USD ($)
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest
Current assets	$ 2,083.0	$ 2,656.7
Net property, plant, and equipment	25,707.4	26,982.4
Current liabilities	$ (4,148.1)	$ (3,753.0)
Tatanka Ridge
Asset Acquisition
Capacity of generation unit | MW	155
Duration of offtake agreement for the sale of energy produced	12 years
Duration of offtake agreement for the sale of energy produced for company 2	10 years
Tatanka Ridge | WECI
Asset Acquisition
Ownership interest in generating facility acquired	85.00%
Total purchase price	$ 239.9
Percent of tax benefits entitled to	99.00%
Number of years will receive tax benefits	11 years
Asset Acquisition - Allocation of Purchase Price to Assets acquired, Liabilities assumed, less Noncontrolling Interest
Current assets	$ 37.3
Net property, plant, and equipment	301.2
Current liabilities	(37.3)
Long-term liabilities	(19.3)
Noncontrolling interest	(42.0)
Total purchase price	$ 239.9