Investments in and Loans to Joint Ventures (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Ohio Castings [Member]
Financial position:
Current assets	$ 21,607	$ 15,214
Non-current assets	9,085	8,651
Total assets	30,692	23,865
Current liabilities	5,673	4,752
Members’ equity (deficit)	25,019	19,113
Total liabilities and members’ deficit	30,692	23,865
Axis [Member]
Financial position:
Current assets	7,510	8,124
Non-current assets	33,838	38,655
Total assets	41,348	46,779
Current liabilities	17,356	12,398
Non-current liabilities	47,253	57,253
Total liabilities	64,609	69,651
Members’ equity (deficit)	(23,261)	(22,872)
Total liabilities and members’ deficit	$ 41,348	$ 46,779