Investments in and Loans to Joint Ventures (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Total investments in and loans to joint ventures	$ 29,122		$ 29,122		$ 31,430
Ohio Castings [Member]
Schedule of Equity Method Investments [Line Items]
Total investments in and loans to joint ventures	7,708		7,708		7,378
Results of operations
Revenues	22,255	12,794	36,264	27,282
Gross profit	2,788	515	2,935	905
Net earnings (loss)	1,896	(116)	1,327	(349)
Axis [Member]
Schedule of Equity Method Investments [Line Items]
Total investments in and loans to joint ventures	21,414		21,414		24,052
Results of operations
Revenues	18,225	12,134	33,076	23,076
Gross profit	1,202	1,302	1,514	1,459
Income (loss) before interest	951	1,056	1,023	981
Net earnings (loss)	$ (281)	$ (300)	$ (1,472)	$ (1,743)