Debt (Details Textual)	12 Months Ended					12 Months Ended				12 Months Ended		12 Months Ended
	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Jul. 01, 2011 USD ($)	Dec. 31, 2012 Line of Credit [Member]	Dec. 31, 2011 Line of Credit [Member]	Dec. 31, 2012 Revolving Credit Facility Expiring In November 2012 [Member]	Dec. 31, 2011 Revolving Credit Facility Expiring In November 2012 [Member]	Jul. 01, 2011 Domestic [Member] USD ($)	Dec. 31, 2012 Foreign [Member] EUR (€)	Dec. 31, 2011 Toledo-Lucas County Port Authority and Dayton-Montgomery County Port Authority [Member] USD ($)	Dec. 31, 2012 Toledo-Lucas County Port Authority and Dayton-Montgomery County Port Authority [Member] USD ($)	Dec. 31, 2012 Lorain Port Authority [Member] USD ($)	Dec. 31, 2011 Lorain Port Authority [Member]
Line of Credit Facility [Line Items]
Facility expiration date						Nov. 30, 2016	Nov. 30, 2016
Maximum borrowing amount under revolving credit agreement	$ 325,000,000.0							$ 325,000,000.0
Additional term loan			100,000,000.0
Outstanding amount	38,200,000
Variable commitment fee	0.25%
Amount of maximum available unused credit	262,700,000
Aggregate available borrowings	189,500,000
Foreign lines of credit committed and secured									3,500,000
Average interest rate on short term debt				2.43%	2.94%
Amount issued in variable rate industrial revenue bonds										8,000,000.0		8,300,000.0
Interest rate on bonds											4.90%
Unamortized balance of the bonds	$ 7,158,000	$ 7,705,000									$ 7,200,000
Variable rate minimum												0.26%	0.20%
Variable rate maximum												0.46%	0.50%