FAIR VALUE MEASUREMENTS (Fair Value Measurement of Assets on Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value, recurring	$ 28,417	$ 28,083	$ 24,327
Fair Value, Inputs, Level 1 | Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value, recurring	14,365	15,255	13,689
Fair Value, Inputs, Level 1 | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value, recurring	14,052	12,828	10,638
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value, recurring	1,349	1,244	1,507
Fair Value, Inputs, Level 2 | Common/Collective Trust Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value, recurring	$ 1,349	$ 1,244	$ 1,507