Divestitures Divestitures- Discontinued Operations (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations (net of tax)		$ 0	$ 17,312
Chemetall Surface Treatment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales			208,187
Cost of goods sold			113,323
Operating expenses, net			62,853
Interest and financing expenses	[1]		10,137
Other income, net			(938)
Income before income taxes			22,812
Income tax expense			5,500
Income from discontinued operations (net of tax)			17,312
Depreciation and amortization			16,943
Capital expenditures			$ 5,747

[1] Interest and financing expenses included the allocation of interest expense not directly attributable to other operations as well as interest expense related to debt to be assumed by the buyer. The allocation of interest expense to discontinued operations was based on the ratio of net assets held for sale to the sum of total net assets plus consolidated debt.