Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash Flows from Operating Activities
Net income	$ 77.7	$ 48.2
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	90.1	107.2
Deferred income tax expense	7.7	15.8
Share-based compensation expense	4.1	4.3
Gain on extinguishment of legacy coal liabilities	(9.5)	0.0
Changes in working capital pertaining to operating activities:
Receivables, net	7.6	24.3
Inventories	(13.2)	(31.3)
Accounts payable	(17.0)	25.5
Accrued liabilities	(35.1)	(6.2)
Interest payable	6.1	6.1
Income taxes	(4.2)	0.7
Other operating activities	(6.4)	(2.0)
Net cash provided by operating activities	107.9	192.6
Cash Flows from Investing Activities
Capital expenditures	(48.1)	(84.5)
Other investing activities	0.5	(0.9)
Net cash used in investing activities	(47.6)	(85.4)
Cash Flows from Financing Activities
Proceeds from revolving facility	11.0	273.0
Repayment of revolving facility	(11.0)	(308.0)
Repayment of financing obligation	0.0	(2.5)
Dividends paid	(27.5)	(22.3)
Cash distribution to noncontrolling interests	(4.4)	(8.1)
Other financing activities	(3.8)	(3.4)
Net cash used in financing activities	(35.7)	(71.3)
Net increase in cash and cash equivalents	24.6	35.9
Cash and cash equivalents at beginning of period	140.1	90.0
Cash and cash equivalents at end of period	164.7	125.9
Supplemental Disclosure of Cash Flow Information
Interest paid	12.2	13.4
Income taxes paid	$ 17.3	$ 13.1