GOODWILL IMPAIRMENT TESTING - Summary of Goodwill (Details) - USD ($) $ in Millions	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Goodwill [Line Items]
Goodwill value	$ 1,475.4		$ 1,474.4
Terminal Values Long-term Growth Rate for Debt-Free Cash Flow	3.00%		3.00%
Bedding
Goodwill [Line Items]
Goodwill value	$ 900.5		$ 900.3
Percentage of fair value in excess of carrying amount (as a percent)		40.00%		54.00%
Work Furniture
Goodwill [Line Items]
Goodwill value	97.9		98.4
Percentage of fair value in excess of carrying amount (as a percent)		74.00%		78.00%
Aerospace Products
Goodwill [Line Items]
Goodwill value	66.5		66.3
Percentage of fair value in excess of carrying amount (as a percent)		44.00%		40.00%
Hydraulic Cylinders
Goodwill [Line Items]
Goodwill value	$ 43.0		$ 41.5
Percentage of fair value in excess of carrying amount (as a percent)		18.00%		32.00%
Minimum
Goodwill [Line Items]
Compound Annual Growth Rate (CAGR) Range for Sales	1.00%
Compound Annual Growth Rate (CAGR) Range for Sales			1.00%
Discount rate ranges (as a percent)	8.00%		10.00%
Maximum
Goodwill [Line Items]
Compound Annual Growth Rate (CAGR) Range for Sales	17.00%
Compound Annual Growth Rate (CAGR) Range for Sales			9.00%
Discount rate ranges (as a percent)	12.00%		12.00%
Less than 50%
Goodwill [Line Items]
Goodwill value	$ 1,010.0		$ 107.8
Terminal Values Long-term Growth Rate for Debt-Free Cash Flow	3.00%		3.00%
Discount rate ranges (as a percent)			12.00%
Less than 50% | Minimum
Goodwill [Line Items]
Compound Annual Growth Rate (CAGR) Range for Sales	1.00%
Compound Annual Growth Rate (CAGR) Range for Sales			4.00%
Discount rate ranges (as a percent)	10.00%
Less than 50% | Maximum
Goodwill [Line Items]
Compound Annual Growth Rate (CAGR) Range for Sales	17.00%
Compound Annual Growth Rate (CAGR) Range for Sales			9.00%
Discount rate ranges (as a percent)	12.00%
50% - 100%
Goodwill [Line Items]
Goodwill value	$ 97.9		$ 998.7
Compound Annual Growth Rate (CAGR) Range for Sales	1.00%
Terminal Values Long-term Growth Rate for Debt-Free Cash Flow	3.00%		3.00%
Discount rate ranges (as a percent)	8.00%		10.00%
50% - 100% | Minimum
Goodwill [Line Items]
Compound Annual Growth Rate (CAGR) Range for Sales			3.00%
50% - 100% | Maximum
Goodwill [Line Items]
Compound Annual Growth Rate (CAGR) Range for Sales			5.00%
101% - 300%
Goodwill [Line Items]
Goodwill value	$ 367.5		$ 248.3
Terminal Values Long-term Growth Rate for Debt-Free Cash Flow	3.00%		3.00%
Discount rate ranges (as a percent)			10.00%
101% - 300% | Minimum
Goodwill [Line Items]
Compound Annual Growth Rate (CAGR) Range for Sales	3.00%
Compound Annual Growth Rate (CAGR) Range for Sales			1.00%
Discount rate ranges (as a percent)	8.00%
101% - 300% | Maximum
Goodwill [Line Items]
Compound Annual Growth Rate (CAGR) Range for Sales	6.00%
Compound Annual Growth Rate (CAGR) Range for Sales			3.00%
Discount rate ranges (as a percent)	10.00%
Greater than 300%
Goodwill [Line Items]
Goodwill value			$ 119.6
Compound Annual Growth Rate (CAGR) Range for Sales			8.00%
Terminal Values Long-term Growth Rate for Debt-Free Cash Flow			3.00%
Discount rate ranges (as a percent)			12.00%