SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)
Net revenues	$ 43,648,567	$ 47,861,711	$ 44,216,594	$ 34,630,092	$ 34,012,130	$ 36,174,386	$ 37,159,873	$ 33,285,816	$ 170,356,964	$ 140,632,205	$ 142,030,027
Operating expenses	40,779,879	40,995,150	40,820,963	31,777,814	32,718,561	36,022,941	31,491,091	30,629,377	154,373,806	130,861,970	127,996,977
Income from operations	2,868,688	6,866,561	3,395,631	2,852,278	1,293,569	151,445	5,668,782	2,656,439	15,983,158	9,770,235	14,033,050
Net income	$ 1,339,643	$ 4,137,080	$ 1,792,758	$ 1,641,367	$ 567,293	$ 11,279	$ 3,558,136	$ 1,539,146	$ 8,910,848	$ 5,675,854	$ 8,236,261
Income per share of common stock
Basic (in dollars per share)	$ 0.08	$ 0.26	$ 0.11	$ 0.10	$ 0.04	$ 0.00	$ 0.22	$ 0.10	$ 0.55	$ 0.35	$ 0.51
Diluted (in dollars per share)	$ 0.08	$ 0.25	$ 0.11	$ 0.10	$ 0.03	$ 0.00	$ 0.22	$ 0.09	$ 0.55	$ 0.35	$ 0.51