FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
FAIR VALUE OF FINANCIAL INSTRUMENTS [Abstract]
Other long-term investments, Supplemental Employee Retirement Plan (SERP)	$ 1,197
Corresponding SERP liability	1,197
Number of tax exempt municipal debt securities	2
Auction rate securities (ARS) par value	8,225
Number of impaired auction rate securities (ARS)	1
Fair value of impaired security	3,041
Par value of impaired security	3,275
Impairment amount of impaired security	$ 234