Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Millions	3 Months Ended			6 Months Ended			12 Months Ended
	Jun. 30, 2025		Jun. 30, 2024	Jun. 30, 2025		Jun. 30, 2024	Dec. 31, 2024
Operating activities:
Net income	$ 59.7		$ 45.6	$ 83.3		$ 84.8
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion, and amortization	56.1		46.6	109.7		89.4
Impairment charge	0.0		5.8	0.0		5.8
Stock-based compensation expense				13.4		14.1
Provision for deferred income taxes				11.9		14.4
Gain on disposition of property, plant, equipment, and other assets	(4.5)		(2.0)	(8.3)		(5.9)
(Gain) loss on sale of businesses	2.8		(12.5)	2.5		(19.5)
(Increase) decrease in other assets				2.3		(4.2)
Increase (decrease) in other liabilities				(3.7)		(9.7)
Other				5.7		(5.7)
Changes in current assets and liabilities:
(Increase) decrease in receivables				(126.3)		(80.6)
(Increase) decrease in inventories				(50.7)		21.9
(Increase) decrease in other current assets				13.4		11.3
Increase (decrease) in accounts payable				60.1		(11.3)
Increase (decrease) in advance billings				(41.8)		(2.3)
Increase (decrease) in accrued liabilities				(11.0)		16.3
Net cash provided by operating activities				60.5		118.8
Investing activities:
Proceeds from disposition of property, plant, equipment, and other assets				10.8		7.4
Proceeds from sale of businesses				0.0		33.3
Capital expenditures				(61.8)		(102.0)
Cash received (paid) for acquisitions				17.6		(179.9)
Net cash required by investing activities				(33.4)		(241.2)
Financing activities:
Payments to retire debt				(6.6)		(63.4)
Proceeds from issuance of debt				0.0		200.0
Dividends paid to common stockholders				(5.0)		(4.9)
Purchase of shares to satisfy employee tax on vested stock				(12.4)		(10.4)
Debt issuance costs				(0.7)		0.0
Net cash (required) provided by financing activities				(24.7)		121.3
Net increase (decrease) in cash and cash equivalents				2.4		(1.1)
Cash and cash equivalents at beginning of period				187.3		104.8	$ 104.8
Cash and cash equivalents at end of period	$ 189.7	[1]	$ 103.7	$ 189.7	[1]	$ 103.7	$ 187.3

[1] (unaudited)