Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 4,262,002	$ 1,641,367
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,643,435	3,375,084
Amortization of deferred loan costs	76,279	107,679
Share based compensation	235,860	268,485
(Recoveries) provision for bad debts	(33,783)	93,171
Gain on disposal of assets	(20,608)
Changes in operating assets and liabilities:
Receivables	250,597	(356,373)
Inventories	17,936	197,061
Prepaid expenses	(729,497)	(425,391)
Accounts payable	290,306	(1,602,224)
Accrued expenses	705,272	552,789
Income taxes	2,156,816	882,250
Net cash provided by operating activities	11,854,615	4,733,898
Cash flows from investing activities:
Proceeds from sale of assets	20,608
Acquisition of property and equipment	(2,395,542)	(1,443,703)
Net cash used in investing activities	(2,374,934)	(1,443,703)
Cash flows from financing activities:
Principal payments on long-term debt	(9,300,000)	(5,700,000)
Net cash used in financing activities	(9,300,000)	(5,700,000)
Net increase (decrease) in cash	179,681	(2,409,805)
Cash and cash equivalents at beginning of period	19,043,213	13,582,659
Cash and cash equivalents at end of period	19,222,894	11,172,854
Supplemental disclosure of cash flow information:
Cash paid for interest	479,180	139,738
Cash paid for income taxes	$ 200,000