Goodwill and Other Intangible Assets - Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Finite-Lived Intangible Assets [Line Items]
Asset impairment charges	$ 1,434	$ 0	$ 0
Finite-lived intangible assets, net	6,938	4,608
Patents trademarks and other [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	10,199	7,758
Finite-lived intangible assets, accumulated amortization	(3,756)	(3,995)
Finite-lived intangible assets, net	6,443	3,763
Note issuance costs [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	2,445	2,445
Finite-lived intangible assets, accumulated amortization	(1,950)	(1,600)
Finite-lived intangible assets, net	$ 495	$ 845