Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Supplemental disclosures of cash flow information:
Cash paid for interest	$ 207.3	$ 218.9	$ 186.3
Cash paid (refunded) for income taxes	(0.7)	4.0	2.2
Cash payments for finance leases included in cash flows from financing activities	0.0	1.2	0.0
Cash payments for operating leases included in cash flows from operating activities	24.6	29.8	0.0
Non-cash investing activities:
Non-cash accrual of property and equipment	(39.6)	(6.5)	6.8
Right-of-use assets obtained in exchange for operating lease liabilities	9.8	104.1	0.0
Discounted secured term loan receivable from contract restructuring	0.0	0.0	47.7
Receivable from sale of VEX	10.0	0.0	0.0
Redemption of non-controlling interest	$ (4.0)	$ 0.0	$ 0.0