Segment Results (Schedule Of Segment Operating Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Total consolidated operating income	$ 18.3	$ 35.8
Building Products [Member]
Segment Reporting Information [Line Items]
Total consolidated operating income	50.8	59.8
Resilient Flooring [Member]
Segment Reporting Information [Line Items]
Total consolidated operating income	(5.4)	5.9
Wood Flooring [Member]
Segment Reporting Information [Line Items]
Total consolidated operating income	1.3	(1.2)
Unallocated Corporate Segment [Member]
Segment Reporting Information [Line Items]
Total consolidated operating income	$ (28.4)	$ (28.7)