Intangible Assets and Goodwill (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Summary of intangible assets and goodwill
Gross	$ 2,576		$ 2,576		$ 2,576
Accumulated Amortization	(2,429)		(2,429)		(2,364)
Impairment
Net	147		147		212
Goodwill (Indefinite life)	2,926		2,926		2,926
Intangible Assets and Goodwill (Additional Textual) [Abstract]
Amortization expense	32,000	32,000	65,000	65,000
Patents (4-10 years) [Member]
Summary of intangible assets and goodwill
Gross	1,914		1,914		1,914
Accumulated Amortization	(1,767)		(1,767)		(1,702)
Impairment
Net	147		147		212
Patents (4-10 years) [Member] | Maximum [Member]
Intangible assets and goodwill (Textual) [Abstract]
Useful life			10 years
Patents (4-10 years) [Member] | Minimum [Member]
Intangible assets and goodwill (Textual) [Abstract]
Useful life			4 years
Trademarks (6 years) [Member]
Summary of intangible assets and goodwill
Gross	69		69		69
Accumulated Amortization	(69)		(69)		(69)
Impairment
Net	0		0		0
Intangible assets and goodwill (Textual) [Abstract]
Useful life			6 years
Other (4 to 6 years) [Member]
Summary of intangible assets and goodwill
Gross	593		593		593
Accumulated Amortization	(593)		(593)		(593)
Impairment
Net	$ 0		$ 0		$ 0
Other (4 to 6 years) [Member] | Maximum [Member]
Intangible assets and goodwill (Textual) [Abstract]
Useful life			6 years
Other (4 to 6 years) [Member] | Minimum [Member]
Intangible assets and goodwill (Textual) [Abstract]
Useful life			4 years