Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred tax liabilities:
Property and equipment	$ 9,205	$ 9,766
Intangible assets	10,437	5,538
Prepaid expenses	616	439
Total deferred tax liabilities	20,258	15,743
Deferred tax assets:
Allowance for doubtful accounts	233	319
Compensation	3,195	3,060
Other accrued liabilities	76	150
Loss carry forwards	58	92
Deferred Tax Assets, Gross	3,562	3,621
Less: valuation allowance	58	92
Total net deferred tax assets	3,504	3,529
Net deferred tax liabilities	16,754	12,214
Current portion of deferred tax assets	892	1,169
Non-current portion of deferred tax liabilities	17,646	13,383
Net deferred tax liabilities	$ (16,754)	$ (12,214)