Segment Results (Schedule Of Segment Operating Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Segment operating income (loss)	$ 63.1	$ 63.6	$ 98.9	$ 117.4
Building Products [Member]
Segment Reporting Information [Line Items]
Segment operating income (loss)	64.2	64.9	124.0	122.7
Resilient Flooring [Member]
Segment Reporting Information [Line Items]
Segment operating income (loss)	23.2	20.7	29.1	31.1
Wood Flooring [Member]
Segment Reporting Information [Line Items]
Segment operating income (loss)	2.5	(2.6)	1.3	2.5
Unallocated Corporate Segment [Member]
Segment Reporting Information [Line Items]
Segment operating income (loss)	$ (26.8)	$ (19.4)	$ (55.5)	$ (38.9)