Derivative Instruments and Fair Value Accounting - Assets and liabilities Measured at fair value on recurring basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Millions		Jun. 30, 2022	Dec. 31, 2021
Level 1
Assets:
Cash equivalents		$ 32.5	$ 11.4
Restricted cash		256.8	135.1
Total assets		289.3	146.5
Level 2 | Other Assets [Member]
Assets:
Foreign currency hedge (1)	[1]	0.8	0.0
Total assets		7.7	0.0
Level 2 | Accrued Liabilities [Member]
Liabilities [Abstract]
Foreign currency hedge (2)	[2]	0.0	0.1
Total liabilities		0.0	21.1
Level 3
Assets:
Total assets		0.0	0.0
Interest Rate Swap [Member] | Level 2 | Accrued Liabilities [Member]
Assets:
Interest Rate Cash Flow Hedge Asset at Fair Value	[1]	6.9	0.0
Liabilities [Abstract]
Interest rate hedge (2)	[2]	$ 0.0	$ 21.0

[1] Included in other assets in our Consolidated Balance Sheets.

[2] Included in accrued liabilities in our Consolidated Balance Sheets.