Segment Results (Tables)

9 Months Ended

Sep. 30, 2022

Segment Reporting [Abstract]

Schedule of Net Sales

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2022		2021		2022		2021
Net sales
Mineral Fiber	$	233.7	$	214.5	$	671.4	$	611.3
Architectural Specialties		91.3		77.7		257.2		212.8
Total net sales	$	325.0	$	292.2	$	928.6	$	824.1

Schedule of Segment Operating Income (Loss)

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2022			2021			2022			2021
Segment operating income (loss)
Mineral Fiber	$	70.8		$	68.5		$	199.8		$	201.2
Architectural Specialties		3.4			5.0			11.0			7.5
Unallocated Corporate		(0.9	)		(1.4	)		(2.7	)		(4.2	)
Total consolidated operating income	$	73.3		$	72.1		$	208.1		$	204.5

Reconciliation of Total Consolidated Operating Income to Earnings Before Income Taxes

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2022			2021			2022			2021
Total consolidated operating income	$	73.3		$	72.1		$	208.1		$	204.5
Interest expense		7.0			6.1			17.9			17.4
Other non-operating (income), net		(1.4	)		(1.4	)		(4.1	)		(4.3	)
Earnings from continuing operations before income taxes	$	67.7		$	67.4		$	194.3		$	191.4

Reconciliation of Total Segment Assets to Total Consolidated Assets

	September 30, 2022		December 31, 2021
Segment assets
Mineral Fiber	$	1,132.6	$	1,133.9
Architectural Specialties		388.7		366.3
Unallocated Corporate		218.1		209.8
Total consolidated assets	$	1,739.4	$	1,710.0