Segments (Schedule of Segment Information) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net sales:
Net sales	$ 405.7	$ 343.8
Segment operating income:
Total segment operating income	22.1	20.5
Litigation settlement gain	0.0	3.3
Other components of net pension income	(2.3)	(1.7)
Interest expense	(8.4)	(7.4)
Income before income taxes	16.0	14.8
Operating Segments
Net sales:
Net sales	405.7	343.8
Segment operating income:
Total segment operating income	30.8	23.7
Operating Segments | Supply Technologies
Net sales:
Net sales	160.9	133.2
Segment operating income:
Total segment operating income	12.5	10.6
Operating Segments | Assembly Components
Net sales:
Net sales	145.4	139.3
Segment operating income:
Total segment operating income	12.6	11.8
Operating Segments | Engineered Products
Net sales:
Net sales	99.4	71.3
Segment operating income:
Total segment operating income	5.7	1.3
Segment Reconciling Items
Segment operating income:
Total segment operating income	22.1	20.5
Corporate costs	(8.7)	(6.5)
Litigation settlement gain	0.0	3.3
Other components of net pension income	2.3	1.7
Interest expense	$ (8.4)	$ (7.4)