UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash Flows From Operating Activities
Net loss	$ (105.0)	$ (1,679.1)
Loss from discontinued operations, net of income taxes	4.3	4.5
Loss from continuing operations, net of income taxes	(100.7)	(1,674.6)
Adjustments to reconcile loss from continuing operations, net of income taxes to net cash used in operating activities:
Depreciation, depletion and amortization	145.4	194.3
Noncash interest expense, net	10.8	8.0
Deferred income taxes	(0.8)	(0.5)
Noncash share-based compensation	3.9	6.1
Asset impairment	0.0	1,418.1
Net gain on disposals	(2.4)	(7.9)
Net gain on early debt extinguishment	(15.3)	0.0
Loss from equity affiliates	4.4	15.1
Foreign currency option contracts	4.3	(1.3)
Changes in current assets and liabilities:
Accounts receivable	(5.9)	138.1
Inventories	29.2	29.9
Other current assets	(19.5)	(13.3)
Accounts payable and accrued expenses	(50.2)	(133.9)
Collateral arrangements	(5.3)	0.0
Asset retirement obligations	14.0	6.9
Workers’ compensation obligations	0.6	(0.5)
Postretirement benefit obligations	(29.3)	(14.8)
Pension obligations	(1.2)	0.2
Other, net	0.0	(2.6)
Net cash used in continuing operations	(18.0)	(32.7)
Net cash used in discontinued operations	(4.8)	(20.4)
Net cash used in operating activities	(22.8)	(53.1)
Cash Flows From Investing Activities
Additions to property, plant, equipment and mine development	(93.9)	(85.8)
Changes in accrued expenses related to capital expenditures	(4.1)	(14.3)
Proceeds from disposal of assets, net of receivables	4.9	12.0
Contributions to joint ventures	(244.5)	(192.0)
Distributions from joint ventures	252.6	188.2
Advances to related parties	(0.2)	(23.1)
Cash receipts from Middlemount Coal Pty Ltd and other related parties	2.6	0.0
Other, net	0.0	(0.6)
Net cash used in investing activities	(82.6)	(115.6)
Cash Flows From Financing Activities
Proceeds from long-term debt	0.0	300.0
Repayments of long-term debt	(83.1)	(9.9)
Payment of debt issuance and other deferred financing costs	(22.5)	0.0
Proceeds from common stock issuances, net of costs	65.1	0.0
Repurchase of employee common stock relinquished for tax withholding	(1.3)	(1.6)
Distributions to noncontrolling interests	(0.1)	(3.5)
Net cash (used in) provided by financing activities	(41.9)	285.0
Net change in cash, cash equivalents and restricted cash	(147.3)	116.3
Cash, cash equivalents and restricted cash at beginning of period	709.2	732.2
Cash, cash equivalents and restricted cash at end of period	$ 561.9	$ 848.5