FAIR VALUE MEASUREMENTS (Fair Value Measurement on Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value, recurring	$ 13,009	$ 20,464	$ 27,183
Level 1 [Member] | Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value, recurring	6,185	11,472	14,549
Level 1 [Member] | Equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value, recurring	6,824	8,992	12,634
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value, recurring	2,682	2,124	1,336
Level 2 [Member] | Money Market Mutual Fund [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value, recurring	$ 2,682	$ 2,124	$ 1,336