Segment Results (Tables)

9 Months Ended

Sep. 30, 2024

Segment Reporting [Abstract]

Schedule of Net Sales

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2024		2023		2024		2023
Net sales
Mineral Fiber	$	258.0	$	249.7	$	747.8	$	712.1
Architectural Specialties		128.6		97.6		330.2		270.8
Total net sales	$	386.6	$	347.3	$	1,078.0	$	982.9

Reconciliation of Total Consolidated Operating Income to Earnings Before Income Taxes

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2024			2023			2024			2023
Segment operating income (loss)
Mineral Fiber	$	93.0		$	85.5		$	253.9		$	224.8
Architectural Specialties		19.2			15.5			41.1			34.9
Unallocated Corporate		(0.9	)		(0.8	)		(2.6	)		(2.3	)
Total consolidated operating income	$	111.3		$	100.2		$	292.4		$	257.4

Schedule of Segment Operating Income (Loss)

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2024			2023			2024			2023
Total consolidated operating income	$	111.3		$	100.2		$	292.4		$	257.4
Interest expense		10.5			8.8			30.6			26.7
Other non-operating (income), net		(3.0	)		(2.3	)		(9.3	)		(6.9	)
Earnings before income taxes	$	103.8		$	93.7		$	271.1		$	237.6

Reconciliation of Total Segment Assets to Total Consolidated Assets

	September 30, 2024		December 31, 2023
Segment assets
Mineral Fiber	$	1,087.2	$	1,091.9
Architectural Specialties		544.9		421.1
Unallocated Corporate		171.9		159.4
Total consolidated assets	$	1,804.0	$	1,672.4