Investment in Unconsolidated Affiliates Summarized Income Statement of Equity Method Investment (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Schedule of Equity Method Investments [Line Items]
Operating revenues	$ 864.4			$ 702.1			$ 3,072.4	$ 1,636.9
Operating Income (Loss)	284.8			258.0			462.9	439.7
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	252.5	$ 112.9	$ 52.7	177.4	$ 85.9	$ (491.8)	418.1	(228.5)
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Schedule of Equity Method Investments [Line Items]
Operating revenues	956.0			596.0			2,713.0	1,759.0
Cost of Revenue	565.0			250.0			1,510.0	653.0
Operating Income (Loss)	152.0			100.0			482.0	326.0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 107.0			$ (173.0)			$ 341.0	$ (35.0)