Investments In Unconsolidated Affiliates - Summarized Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		5 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Variable Interest Entity [Line Items]
Total assets	$ 259.9			$ 259.9		$ 291.3
Revenues	293.1	$ 294.9		583.8	$ 578.0
Loss before provision for income taxes and equity in net income of affiliates	82.3	59.8		135.0	109.8
Net earnings	39.1	32.6		89.2	58.6
Net earnings	39.1	32.6		89.2	$ 58.6
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Current assets	489.0			489.0		417.9
Non-current assets	8,496.1			8,496.1		8,694.9
Total assets	8,985.1			8,985.1		9,112.8
Current liabilities, including short-term debt	2,453.6			2,453.6		1,090.4
Non-current liabilities	5,142.5			5,142.5		5,412.9
Cumulative preferred series A stock	7,596.1			7,596.1		6,503.3
Cumulative preferred series A stock	0.0			0.0		1,030.6
Total capital	1,389.0			1,389.0		1,578.9
Total liabilities and partners' capital	8,985.1			8,985.1		$ 9,112.8
Revenues	420.6	398.9	$ 573.0	815.9
Loss before provision for income taxes and equity in net income of affiliates	(201.9)	(86.4)	(198.3)	(202.9)
Net earnings	(173.8)	(60.5)	(141.9)	(99.9)
Net earnings	$ (207.1)	$ (94.0)	$ (193.7)	$ (165.6)