Revenue - By Major Source (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Net sales	$ 1,046.7	$ 1,091.5	$ 1,102.5	$ 1,028.8	$ 984.5	$ 1,009.7	$ 989.3	$ 960.3	$ 4,269.5	$ 3,943.8	$ 3,749.9
Residential Products
Disaggregation of Revenue [Line Items]
Net sales									1,703.7	1,620.2	1,571.4
Residential Products | Bedding group
Disaggregation of Revenue [Line Items]
Net sales									905.1	837.2	831.8
Residential Products | Fabric & Flooring Products group
Disaggregation of Revenue [Line Items]
Net sales									735.8	720.1	666.8
Residential Products | Machinery group
Disaggregation of Revenue [Line Items]
Net sales									62.8	62.9	72.8
Industrial Products
Disaggregation of Revenue [Line Items]
Net sales									367.4	291.7	289.4
Industrial Products | Wire group
Disaggregation of Revenue [Line Items]
Net sales									367.4	291.7	289.4
Furniture Products
Disaggregation of Revenue [Line Items]
Net sales									1,142.1	1,096.4	989.3
Furniture Products | Consumer Products group
Disaggregation of Revenue [Line Items]
Net sales									460.2	413.3	327.2
Furniture Products | Home Furniture group
Disaggregation of Revenue [Line Items]
Net sales									388.6	410.2	413.3
Furniture Products | Work Furniture group
Disaggregation of Revenue [Line Items]
Net sales									293.3	272.9	248.8
Specialized Products
Disaggregation of Revenue [Line Items]
Net sales									1,056.3	935.5	899.8
Specialized Products | Automotive group
Disaggregation of Revenue [Line Items]
Net sales									823.3	772.5	695.0
Specialized Products | Aerospace Products group
Disaggregation of Revenue [Line Items]
Net sales									148.9	137.9	129.7
Specialized Products | Hydraulic Cylinders group
Disaggregation of Revenue [Line Items]
Net sales									84.1	0.0	0.0
Specialized Products | Commercial Vehicle Products (CVP) group
Disaggregation of Revenue [Line Items]
Net sales									$ 0.0	$ 25.1	$ 75.1