Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Estimated useful life [Abstract]
Amortization expense	$ 227	$ 227
Intangible assets, net [Abstract]
Gross Carrying Amount	8,835		8,888
Accumulated Amortization	(7,637)		(7,447)
Net Carrying Amount	1,198		1,441
Trademarks [Member]
Intangible assets, net [Abstract]
Gross Carrying Amount	1,278		1,278
Accumulated Amortization	(864)		(831)
Net Carrying Amount	414		447
Trademarks [Member] | Minimum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets	1 year
Trademarks [Member] | Maximum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets	10 years
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
Accumulated Amortization	(3,389)		(3,259)
Net Carrying Amount	261		391
Contracts Owned Equipment [Member]
Intangible assets, net [Abstract]
Gross Carrying Amount	3,907		3,960
Accumulated Amortization	(3,384)		(3,357)
Net Carrying Amount	$ 523		$ 603
Contracts Owned Equipment [Member] | Minimum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets	5 years
Contracts Owned Equipment [Member] | Maximum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets	7 years