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Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Related Party Transaction
General and administrative expense	$ 9.0	$ 7.0	$ 30.0	$ 20.0
RENOM
Related Party Transaction
Expenses from transactions with related party	9.0	8.0	27.0	22.0
Due to affiliate	9.0		9.0		$ 7.0
CEG
Related Party Transaction
Expenses from transactions with related party	3.0	$ 2.0	7.0	$ 5.0
General and administrative expense	$ 0.6		$ 2.0