Intangible Assets - Indefinite Lived Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Indefinite-lived Intangible Assets by Major Class [Line Items]
Goodwill	$ 9,900	[1]	$ 9,900	[1]
Total unamortized intangible assets	10,293		11,219
Use rights and other [Member]
Indefinite-lived Intangible Assets by Major Class [Line Items]
Use rights and other	$ 393		$ 1,319

[1] Goodwill primarily relates to our Construction segment.