Segment Results (Schedule Of Net Sales To External Customers) (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 net sales to external customers	$ 729.7	$ 694.7	$ 2,058.6	$ 2,006.1
Building Products [Member]
Segment Reporting Information [Line Items]
Total net sales to external customers	335.5	325.9	944.6	926.1
Resilient Flooring [Member]
Segment Reporting Information [Line Items]
Total net sales to external customers	246.2	246.4	713.1	727.2
Wood Flooring [Member]
Segment Reporting Information [Line Items]
Total net sales to external customers	$ 148.0	$ 122.4	$ 400.9	$ 352.8