Revenue (Tables)

6 Months Ended

Jun. 30, 2018

Mineral Fiber [Member]

Disaggregation Of Revenue [Line Items]

Schedule of Net Sales by Major Customer Group within Each Segment

The following tables provide net sales by major customer group within the Mineral Fiber and Architectural Specialties segments for the three and six months ended June 30, 2018 and 2017:

	Three months ended June 30				Six months ended June 30
Mineral Fiber	2018		2017		2018		2017
Distributors	$	156.7	$	141.6	$	294.4	$	277.8
Home centers		20.5		18.7		44.5		44.4
Direct customers		16.8		16.8		30.5		31.7
Retailers and other		12.7		13.0		28.0		26.0
Total	$	206.7	$	190.1	$	397.4	$	379.9

Architectural Specialties [Member]

Disaggregation Of Revenue [Line Items]

Schedule of Net Sales by Major Customer Group within Each Segment

	Three months ended June 30				Six months ended June 30
Architectural Specialties	2018		2017		2018		2017
Distributors	$	33.4	$	28.0	$	61.8	$	51.4
Direct customers		7.5		6.5		15.4		12.1
Retailers and other		1.0		1.0		1.3		2.0
Total	$	41.9	$	35.5	$	78.5	$	65.5