CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 9.6	$ 0.1
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	61.8	55.8
Deferred income taxes	0.2	(0.1)
Provision for doubtful accounts	2.9	7.3
Gain on sale of assets, net		(0.3)
Amortization of debt issuance costs and discount	1.2	1.2
Non-cash compensation	3.1	2.7
Other non-cash items	(0.1)
Changes in operating assets and liabilities:
Receivables and other operating assets	(0.7)	(12.2)
Payables and accruals	(0.4)	(2.1)
Net cash provided by operating activities	77.6	52.4
Cash flows from investing activities:
Capital expenditures	(59.3)	(58.0)
Other investing activities	0.4	(1.1)
Net cash used in investing activities	(58.9)	(59.1)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	31.0	41.0
Payments on long-term debt and finance lease obligations	(19.4)	(17.8)
Purchase of shares	(6.6)	(0.7)
Net cash provided by financing activities	5.0	22.5
Increase in cash and cash equivalents	23.7	15.8
Cash and cash equivalents, beginning of period	12.4	21.0
Cash and cash equivalents, end of period	36.1	36.8
Supplemental disclosures of cash flow information:
Cash paid during the periods for interest	30.7	31.4
Non-cash operating activities
Operating lease additions	0.1	2.4
Non-cash financing activities:
Finance lease additions	2.8	1.2
Capital expenditure accounts payable and accruals	$ 17.0	$ 13.8