Leasehold Improvements, Equipment and Construction in Progress, Net (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Leasehold Improvements, Equipment and Construction in Progress, Net
Leasehold improvements, equipment and construction in progress, gross	$ 49,953		$ 49,953		$ 48,520
Less accumulated depreciation and amortization	(33,307)		(33,307)		(31,788)
Leasehold improvements, equipment and construction in progress, net	16,646		16,646		16,732
Depreciation expense	1,053	1,066	3,216	3,013
(Gains) losses on sale and abandonment of leasehold improvements and equipment	12	13	56	49
Equipment
Leasehold Improvements, Equipment and Construction in Progress, Net
Leasehold improvements, equipment and construction in progress, gross	12,022		12,022		12,021
Equipment | Minimum
Leasehold Improvements, Equipment and Construction in Progress, Net
Ranges of Estimated useful life			2 years
Equipment | Maximum
Leasehold Improvements, Equipment and Construction in Progress, Net
Ranges of Estimated useful life			5 years
Software
Leasehold Improvements, Equipment and Construction in Progress, Net
Leasehold improvements, equipment and construction in progress, gross	13,119		13,119		12,643
Software | Minimum
Leasehold Improvements, Equipment and Construction in Progress, Net
Ranges of Estimated useful life			3 years
Software | Maximum
Leasehold Improvements, Equipment and Construction in Progress, Net
Ranges of Estimated useful life			10 years
Vehicles
Leasehold Improvements, Equipment and Construction in Progress, Net
Ranges of Estimated useful life			4 years
Leasehold Improvements, Equipment and Construction in Progress, Net
Leasehold improvements, equipment and construction in progress, gross	9,361		9,361		9,405
Other
Leasehold Improvements, Equipment and Construction in Progress, Net
Ranges of Estimated useful life			10 years
Leasehold Improvements, Equipment and Construction in Progress, Net
Leasehold improvements, equipment and construction in progress, gross	2,542		2,542		2,464
Leasehold improvements
Leasehold Improvements, Equipment and Construction in Progress, Net
Leasehold improvements, equipment and construction in progress, gross	9,414		9,414		9,732
Leasehold improvements | Maximum
Leasehold Improvements, Equipment and Construction in Progress, Net
Ranges of Estimated useful life			10 years
Construction in progress
Leasehold Improvements, Equipment and Construction in Progress, Net
Leasehold improvements, equipment and construction in progress, gross	$ 3,495		$ 3,495		$ 2,255