Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net sales to external customers:
Net sales	$ 750.6	$ 673.6	$ 1,454.4	$ 1,357.6
Segment EBIT:
Total EBIT for reportable segments	94.6	85.3	168.4	151.1
Unallocated corporate expenses	(12.9)	(13.4)	(25.8)	(23.9)
Continued Dumping & Subsidy Offset Act (CDSOA) receipts, net of expense	0.0	6.1	0.0	53.8
Interest expense	(8.5)	(8.7)	(16.4)	(17.1)
Investment Income, Interest	0.7	0.4	1.3	0.7
Income (Loss) Before Income Taxes	73.9	69.7	127.5	164.6
Corporate Segment [Member]
Segment EBIT:
Continued Dumping & Subsidy Offset Act (CDSOA) receipts, net of expense			0.0	53.8
Mobile Industries [Member]
Net sales to external customers:
Net sales	408.4	367.8	791.4	751.0
Segment EBIT:
Total EBIT for reportable segments	34.4	37.4	65.2	69.4
Process Industries [Member]
Net sales to external customers:
Net sales	342.2	305.8	663.0	606.6
Segment EBIT:
Total EBIT for reportable segments	$ 60.2	$ 47.9	$ 103.2	$ 81.7