Segment Results (Reconciliation Of Total Segment Assets To Total Consolidated Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total consolidated assets	$ 2,625.9	$ 2,687.2
Building Products [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	1,535.1	1,068.9
Resilient Flooring [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	509.4	510.2
Wood Flooring [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	346.7	337.4
Unallocated Corporate Segment [Member]
Segment Reporting Information [Line Items]
Total consolidated assets	$ 234.7	$ 770.7