CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 4,511	$ 2,120
Receivables, net	32,254	33,947
Prepaid expenses and other current assets	2,510	3,161
Deferred income taxes	597	1,276
Total current assets	39,872	40,504
Property and equipment, net	113,319	109,792
Restricted cash	4,111	4,111
Intangible assets, net	39,536	40,771
Goodwill	22,617	23,105
Other assets	491	411
Total assets	219,946	218,694
Current Liabilities:
Accounts payable	6,842	6,333
Deferred revenue	5,147	3,919
Accrued liabilities	7,093	7,322
Accrued salaries and benefits	4,402	7,570
Income taxes payable	3,947	426
Current portion of closure and post-closure obligations	978	1,913
Total current liabilities	28,409	27,483
Long-term closure and post-closure obligations	15,608	15,449
Reducing revolving line of credit	41,000	45,000
Other long-term liabilities	102	114
Unrecognized tax benefits	470	467
Deferred income taxes	16,482	18,159
Total liabilities	102,071	106,672
Commitments and contingencies
Stockholders' Equity:
Common stock $0.01 par value, 50,000 authorized; 18,444 and 18,385 shares issued, respectively	184	184
Additional paid-in capital	64,537	63,969
Retained earnings	53,830	48,424
Treasury stock, at cost, 33 and 71 shares, respectively	(554)	(1,183)
Accumulated other comprehensive income (loss)	(122)	628
Total stockholders' equity	117,875	112,022
Total liabilities and stockholders' equity	$ 219,946	$ 218,694