Summary of Significant Accounting Policies (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, plant and equipment
Depreciation expense	$ 2,819	$ 2,975	$ 5,704
Repairs and maintenance expenses	$ 2,855	$ 4,025	$ 2,909
Land improvements and buildings | Minimum
Property, plant and equipment
Estimated useful lives	15 years
Land improvements and buildings | Maximum
Property, plant and equipment
Estimated useful lives	40 years
Machinery and equipment | Minimum
Property, plant and equipment
Estimated useful lives	3 years
Machinery and equipment | Maximum
Property, plant and equipment
Estimated useful lives	20 years
Furniture and fixtures | Minimum
Property, plant and equipment
Estimated useful lives	3 years
Furniture and fixtures | Maximum
Property, plant and equipment
Estimated useful lives	12 years
Mobile equipment and other | Minimum
Property, plant and equipment
Estimated useful lives	3 years
Mobile equipment and other | Maximum
Property, plant and equipment
Estimated useful lives	10 years