Summary of Significant Accounting Policies - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Cash and cash equivalents	$ 18.1	$ 23.7	$ 43.8	$ 23.3
Restricted cash included in other assets	2.6	1.4	1.5	1.4
Total cash and cash equivalents and restricted cash	20.7	25.1	45.3	24.7
Cash and cash equivalents		180.3		216.0
Restricted cash classified in Assets held for sale	0.0	0.2	0.2	0.2
Total cash and cash equivalents and restricted cash classified in Assets held for sale	253.7	180.5	$ 195.4	$ 216.2
Supplemental cash flow information:
Cash paid for interest	12.3	33.0
Cash paid for taxes, net of refunds	2.6	8.0
Non-cash investing and financing activities:
Property, plant and equipment included in accounts payable	2.1	4.9
Investments included in accounts receivable	0.0	20.0
Investments included in accounts payable	0.0	8.5
Extinguishment of convertible note in exchange	51.8	0.0
Issuance of convertible note in exchange	(51.8)	0.0
Debt assumed in acquisitions	$ 6.3	$ 0.0