Summary of Significant Accounting Policies - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 55.5	$ 28.2	$ 55.5	$ 28.2	$ 43.8	$ 23.3
Restricted cash included in other assets	8.6	1.6	8.6	1.6	1.5	1.4
Total cash and cash equivalents and restricted cash	64.1	29.8	64.1	29.8	45.3	24.7
Supplemental cash flow information:
Cash paid for interest			31.3	35.0
Cash paid for taxes, net of refunds			4.3	8.5
Non-cash investing and financing activities:
Property, plant and equipment included in accounts payable			2.1	3.0
Investments included in accounts receivable			0.0	0.0
Investments included in accounts payable			0.0	10.0
Issuance of stock	40.9	5.6		5.6
Issuance of redeemable noncontrolling interest			40.9	0.0
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
Preferred stock
Non-cash investing and financing activities:
Issuance of stock	19.1		19.1	0.0
Discontinued Operations
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents classified in assets held for sale	0.0	135.6	0.0	135.6	195.2	216.0
Restricted cash classified in Assets held for sale	0.0	0.2	0.0	0.2	0.2	0.2
Total cash and cash equivalents and restricted cash classified in Assets held for sale	$ 0.0	$ 135.8	$ 0.0	$ 135.8	$ 195.4	$ 216.2