EQUITY-BASED COMPENSATION (Schedule of Equity-based Compensation Expense for Restricted Stock Awards and Non-Qualified Stock Options) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	$ 2,102	$ 1,795	$ 4,184	$ 3,587
Income tax benefits	(736)	(628)	(1,464)	(1,255)
Total equity-based compensation expense, net of tax	1,366	1,167	2,720	2,332
Cost of Revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	148	68	267	68
Selling and Marketing Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	424	282	784	546
Research and Development Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	135	116	276	325
General and Administrative Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	$ 1,395	$ 1,329	$ 2,857	$ 2,648