Related Party Transactions (Management) (Narrative) (Details) - Management [Member] - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Equipment, Supplies and Services [Member]
Related Party Transaction [Line Items]
Payments, related party	$ 20.5	$ 25.3
Payables, related party	10.4		$ 8.9
Revenue, related party	1.1	1.0
Receivables, net, related party	0.2		0.5
Subcontracting Arrangements [Member]
Related Party Transaction [Line Items]
Payments, related party	29.0	$ 0.7
Payables, related party	$ 18.6		$ 1.4

Amount for accounts payable to related parties.

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