Segment Results (Schedule Of Segment Operating Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Segment operating income (loss)	$ 57.8	$ 67.6	$ 110.3	$ 114.6
Building Products [Member]
Segment Reporting Information [Line Items]
Segment operating income (loss)	64.9	64.7	122.7	124.0
Resilient Flooring [Member]
Segment Reporting Information [Line Items]
Segment operating income (loss)	15.1	17.7	24.5	24.1
Wood Flooring [Member]
Segment Reporting Information [Line Items]
Segment operating income (loss)	(2.6)	2.5	2.5	3.0
Unallocated Corporate Segment [Member]
Segment Reporting Information [Line Items]
Segment operating income (loss)	$ (19.6)	$ (17.3)	$ (39.4)	$ (36.5)