MARKETABLE SECURITIES - Amortized cost basis, fair value and net unrealized gains on available-for-sale securities (Details 2) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	$ 35,007	$ 37,399
Fair Value	35,113	37,484
Net Unrealized Gains (Losses)	106	85
Municipal Obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	30,014	31,990
Fair Value	30,098	32,080
Net Unrealized Gains (Losses)	84	90
Corporate Obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost Basis	4,993	5,409
Fair Value	5,015	5,404
Net Unrealized Gains (Losses)	$ 22	$ (5)