Segment Results (Schedule Of Segment Operating Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
Total consolidated operating income (loss)	$ 93.6	$ 108.6	$ 208.2	$ 228.9
Building Products [Member]
Segment Reporting Information [Line Items]
Total consolidated operating income (loss)	86.7	81.1	210.7	177.9
Resilient Flooring [Member]
Segment Reporting Information [Line Items]
Total consolidated operating income (loss)	22.5	25.3	46.6	57.9
Wood Flooring [Member]
Segment Reporting Information [Line Items]
Total consolidated operating income (loss)	2.6	13.5	5.6	29.8
Unallocated Corporate Segment [Member]
Segment Reporting Information [Line Items]
Total consolidated operating income (loss)	$ (18.2)	$ (11.3)	$ (54.7)	$ (36.7)