SEGMENT INFORMATION - Average Assets for Segments (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Total assets	$ 5,341.8	$ 5,307.3
Operating segments | Bedding Products
Segment Reporting Information [Line Items]
Total assets	947.2	836.0
Operating segments | Specialized Products
Segment Reporting Information [Line Items]
Total assets	335.5	316.7
Operating segments | Furniture, Flooring & Textile Products
Segment Reporting Information [Line Items]
Total assets	402.1	373.5
Operating segments | Average current liabilities included in segment numbers above
Segment Reporting Information [Line Items]
Total assets	833.3	814.1
Unallocated assets
Segment Reporting Information [Line Items]
Total assets	2,791.5	2,828.5
Difference between average assets and period-end balance sheet
Segment Reporting Information [Line Items]
Total assets	$ 32.2	$ 138.5