Intangible Assets (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
Estimated useful life [Abstract]
Amortization expense	$ 225	$ 343	$ 452	$ 686
Intangible assets, net [Abstract]
Gross Carrying Amount	8,800		8,800		8,852
Accumulated Amortization	(6,940)		(6,940)		(6,519)
Net Carrying Amount	1,860		1,860		2,333
Trademarks [Member]
Intangible assets, net [Abstract]
Gross Carrying Amount	1,277		1,277		1,278
Accumulated Amortization	(766)		(766)		(702)
Net Carrying Amount	511		511		576
Trademarks [Member] | Maximum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets			10 years
Trademarks [Member] | Minimum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets			1 year
Contracts - third party [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets			7 years
Intangible assets, net [Abstract]
Gross Carrying Amount	3,650		3,650		3,650
Accumulated Amortization	(2,998)		(2,998)		(2,738)
Net Carrying Amount	652		652		912
Contracts - owned equipment [Member]
Intangible assets, net [Abstract]
Gross Carrying Amount	3,873		3,873		3,924
Accumulated Amortization	(3,176)		(3,176)		(3,079)
Net Carrying Amount	$ 697		$ 697		$ 845
Contracts - owned equipment [Member] | Maximum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets			7 years
Contracts - owned equipment [Member] | Minimum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets			5 years