Income Taxes (Details) - USD ($) $ / shares in Units, $ in Millions			10 Months Ended	12 Months Ended
		Mar. 05, 2020	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components of Benefit From (Provision For) Income Taxes:
Maximum percent of qualifying income for publicly traded partnerships to be treated as corporations				90.00%
Texas Margin Tax	[1]			$ (32.1)	$ (44.2)	$ (54.8)
Other				1.1	(1.4)	(5.5)
Benefit from (provision for) income taxes				124.3	(45.6)	(60.3)
Liquidity Option liability		$ 511.9	$ 0.0	$ 0.0	509.6
Series A cumulative convertible preferred units (in dollars per unit)			$ 1,000	$ 1,000
OTA Holdings, Inc. [Member]
Components of Benefit From (Provision For) Income Taxes:
Benefit from (provision for) income taxes		$ 72.2	$ 83.1	$ 155.3	$ 0.0	$ 0.0

[1] Although the Texas Margin Tax is not considered a state income tax, it has the characteristics of an income tax since it is determined by applying a tax rate to a base that considers our Texas-sourced revenues and expenses.