PREPAID EXPENSES AND OTHER CURRENT ASSETS AND ACCRUED EXPENSES (Schedule of Accrued Expenses) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
PREPAID EXPENSES AND OTHER CURRENT ASSETS AND ACCRUED EXPENSES [Abstract]
Accrued wages and wage related taxes	$ 9,778	$ 9,047
Accrued sales commissions	6,190	4,357
Employee benefits	1,406	945
Accrued professional fees	1,998	1,768
Deferred revenue	8,735	8,218
Deferred rent	1,467	1,497
Other	2,519	3,167
Accrued Liabilities, Current, Total	$ 32,093	$ 28,999