Segment Results (Schedule Of Net Sales To External Customers) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Total net sales to external customers	$ 706.6	$ 675.4	$ 1,328.9	$ 1,311.4
Building Products [Member]
Segment Reporting Information [Line Items]
Total net sales to external customers	316.3	297.1	609.1	600.2
Resilient Flooring [Member]
Segment Reporting Information [Line Items]
Total net sales to external customers	252.1	253.5	466.9	480.8
Wood Flooring [Member]
Segment Reporting Information [Line Items]
Total net sales to external customers	$ 138.2	$ 124.8	$ 252.9	$ 230.4