Dispositions (Details) - USD ($) $ in Millions			12 Months Ended
	Sep. 03, 2013	Aug. 01, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Select financial information of discontinued operations:
Income from discontinued operations, net of taxes			$ 0.0	$ 0.0	$ 3.0
Southwest Steel Processing LLC
Select financial information of discontinued operations:
Sale of noncontrolling interest		25.00%
Proceeds from sale of noncontrolling interest		$ 5.0
Non-core Business Unit | Supply Technologies | Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of non-core business unit	$ 8.5
Select financial information of discontinued operations:
Net sales				5.2
Loss from discontinued operations before tax				(1.3)
Income tax benefit from operations				0.5
Net loss from discontinued operations				(0.8)
Gain on sale of business before tax				5.3
Income tax expense from gain on sale of business				(1.5)
Net gain on sale of business				3.8
Income from discontinued operations, net of taxes				$ 3.0