Acquisitions - Blooming Grove (Details) - Subsequent event - Blooming Grove Wind Energy Center $ in Millions	Feb. 19, 2020 USD ($)	Jan. 27, 2020 USD ($) MW
Business Acquisition [Line Items]
Capacity of generation unit | MW		250
Bonus depreciation percentage		100.00%
WECI
Business Acquisition [Line Items]
Ownership interest in wind generating facility acquired		80.00%
Acquisition purchase price | $	$ 44	$ 345
Additional ownership interest acquired	10.00%