Investments in and Loans to Joint Ventures (Details 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Ohio Castings [Member]
Results of operations
Revenues	$ 13,683	$ 20,507	$ 27,337	$ 43,895
Gross profit	1,004	2,314	1,214	4,362
Net earnings/(loss)	218	1,397	(380)	2,529
Axis [Member]
Results of operations
Revenues	16,086	19,077	32,497	39,417
Gross profit	4,818	5,214	9,860	10,277
Income (loss) before interest	4,567	4,975	9,335	9,764
Net earnings/(loss)	$ 3,710	$ 3,886	$ 7,564	$ 7,550