SELECTED QUARTERLY INFORMATION (UNAUDITED) (Details) (USD $) In Thousands, unless otherwise specified	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, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
SELECTED QUARTERLY INFORMATION (UNAUDITED)
Total revenue	$ 122,737	$ 139,613	$ 146,334	$ 110,058	$ 119,142	$ 128,605	$ 129,090	$ 104,567	$ 109,013	$ 124,640	$ 131,082	$ 105,934	$ 518,742	$ 481,404	$ 470,669
Gross profit	46,718	54,960	57,630	44,612	47,646	50,790	52,527	41,686	44,716	48,545	52,036	42,003	203,920	192,649	187,300
Net income (loss)	(1,071)	3,264	7,178	4	(669)	1,979	5,190	(2,593)	(12,526)	1,759	1,721	(9,727)	9,375	3,907	(18,773)
Financing expense for legal and other costs									$ 7,100	$ 200	$ 300	$ 6,800		$ (19)	$ 14,364