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
	Mar. 31, 2013	Mar. 31, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	$ 1,674	$ 2,082
Income tax benefits	(586)	(729)
Total equity-based compensation expense, net of tax	1,088	1,353
Cost of revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	160	119
Selling and marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	602	360
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	205	141
General and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Equity-based compensation expense	$ 707	$ 1,462