CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income	$ 15,536	$ 10,374
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	12,157	13,504
Amortization of deferred loan costs	229	229
Stock-based compensation	938	877
Excess tax benefit from stock-based compensation	(286)	(395)
Provision for bad debts	80	79
(Gain) loss on disposition of assets	(20)	249
Changes in operating assets and liabilities:
Receivables	(703)	(969)
Inventories	158	59
Prepaid expenses	(684)	(666)
Accounts payable	201	(795)
Accrued expenses	665	(172)
Income taxes receivable	160	408
Net cash provided by operating activities	28,431	22,782
Cash flows from investing activities:
Proceeds from sale of assets	23	84
Change in construction payable	1,903	766
Acquisition of property and equipment	(26,575)	(13,019)
Net cash used in investing activities	(24,649)	(12,169)
Cash flows from financing activities:
Net exercise of stock options	1,986	(2,428)
Excess tax benefit from stock-based compensation	286	395
Principal payments on long-term debt	(8,400)	(10,400)
Net cash used in financing activities	(6,128)	(12,433)
Net decrease in cash	(2,346)	(1,820)
Cash and cash equivalents at beginning of period	21,583	19,330
Cash and cash equivalents at end of period	19,237	17,510
Supplemental disclosure of cash flow information:
Cash paid for interest, net of amounts capitalized	308	607
Cash paid for income taxes	$ 8,050	$ 5,550