CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current assets:
Accounts receivable, net of allowance for doubtful accounts	$ 67,640	$ 64,883
Property and equipment, net of accumulated depreciation and amortization	127,798	102,897
Intangible assets, net of accumulated amortization	13,226	12,506
Long-term liabilities:
Unfavorable lease obligations, net of accumulated amortization	$ 20,753	$ 19,298
Stockholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	3,333	3,333
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	41,667	41,667
Common stock, shares issued (in shares)	25,146	24,974
Common stock, shares outstanding (in shares)	25,146	24,974