Statements of Consolidated Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating Activities:
Net loss	$ (72.7)	$ (32.8)
Adjustments to reconcile net loss to cash flows from operating activities:
Depreciation and amortization	68.3	69.9
Lease amortization and accretion expense	71.1	83.5
Lease payments	(74.6)	(55.7)
Paid-in-kind interest	4.6	38.8
Debt-related amortization	11.5	6.0
Equity-based compensation and employee benefits expense	8.6	10.5
Non-union pension settlement charge	0.3	0.0
(Gains) losses on property disposals, net	1.3	(45.3)
Deferred income tax benefit, net	(1.0)	0.1
Other noncash items, net	0.8	(1.2)
Changes in assets and liabilities, net:
Accounts receivable	(128.5)	(31.9)
Accounts payable	44.0	22.0
Other operating assets	1.2	8.6
Other operating liabilities	52.4	141.1
Net cash provided by (used in) operating activities	(12.7)	213.6
Investing Activities:
Acquisition of property and equipment	(346.2)	(24.1)
Proceeds from disposal of property and equipment	0.6	54.1
Net cash provided by (used in) investing activities	(345.6)	30.0
Financing Activities:
Issuance of long-term debt, net	306.3	0.0
Repayment of long-term debt	(1.1)	(28.2)
Debt issuance costs	(0.2)	(3.8)
Payments for tax withheld on equity-based compensation	(0.4)	(0.6)
Net cash provided by (used in) financing activities	304.6	(32.6)
Net Increase (Decrease) In Cash and Cash Equivalents and Restricted Amounts Held in Escrow	(53.7)	211.0
Cash and Cash Equivalents and Restricted Amounts Held in Escrow, Beginning of Period	478.0	109.2
Cash and Cash Equivalents and Restricted Amounts Held in Escrow, End of Period	424.3	320.2
Supplemental Cash Flow Information:
Interest paid	$ (56.1)	$ (22.1)