Revenue (Summary of Disaggregation of Revenue by Product Line) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenues	$ 360.4	$ 340.2	$ 228.3	$ 366.3	$ 379.5	$ 403.4	$ 415.3	$ 420.1	$ 1,295.2	$ 1,618.3	$ 1,658.1
Supply Technologies Segment
Disaggregation of Revenue [Line Items]
Total revenues									510.1	611.5	636.8
Supply Technologies Segment | Supply Technologies
Disaggregation of Revenue [Line Items]
Total revenues									444.8	532.9
Supply Technologies Segment | Engineered specialty fasteners and other products
Disaggregation of Revenue [Line Items]
Total revenues									65.3	78.6
Assembly Components Segment
Disaggregation of Revenue [Line Items]
Total revenues									441.5	539.5	578.3
Assembly Components Segment | Fuel, rubber and plastic products
Disaggregation of Revenue [Line Items]
Total revenues									298.4	353.8
Assembly Components Segment | Aluminum products
Disaggregation of Revenue [Line Items]
Total revenues									143.1	185.7
Engineered Products
Disaggregation of Revenue [Line Items]
Total revenues									343.6	467.3	$ 443.0
Engineered Products | Industrial equipment
Disaggregation of Revenue [Line Items]
Total revenues									238.2	323.8
Engineered Products | Forged and machined products
Disaggregation of Revenue [Line Items]
Total revenues									$ 105.4	$ 143.5