Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE MEASUREMENTS (Details)

v3.8.0.1
FAIR VALUE MEASUREMENTS (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Amortized Cost Basis $ 74,883 $ 73,633
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax (37) (25)
Available-for-sale Securities 74,846 73,608
Municipal Bonds and Notes [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Amortized Cost Basis 5,155 13,320
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax (1) (1)
Available-for-sale Securities 5,154 13,319
Corporate Debt Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Amortized Cost Basis 54,075 49,432
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax (36) (24)
Available-for-sale Securities 54,039 49,408
Financial Institution Instruments [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale Securities, Amortized Cost Basis 15,653 10,881
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax 0 0
Available-for-sale Securities $ 15,653 $ 10,881