FAIR VALUE OF ASSETS AND LIABILITIES (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Investments measured at fair value on a recurring basis
Maximum percentage of assets measured using Level 3 valuation methodologies to total assets		1.00%
Recurring basis
Investments measured at fair value on a recurring basis
Money market funds	$ 1,272	$ 1,267
Total	9,446	8,932
Recurring basis | Auction-rate securities
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	1,066	1,066
Recurring basis | Institutional money market funds
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	2,197	2,039
Recurring basis | Fixed income
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	1,092	984
Recurring basis | Marketable equity securities
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	3,819	3,576
Recurring basis | Total institutional funds - Deferred compensation plan
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	7,108	6,599
Recurring basis | Total other assets [Domain]
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	8,174	7,665
Recurring basis | Level 1
Investments measured at fair value on a recurring basis
Money market funds	1,272	1,267
Total	8,380	7,866
Recurring basis | Level 1 | Institutional money market funds
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	2,197	2,039
Recurring basis | Level 1 | Fixed income
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	1,092	984
Recurring basis | Level 1 | Marketable equity securities
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	3,819	3,576
Recurring basis | Level 1 | Total institutional funds - Deferred compensation plan
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	7,108	6,599
Recurring basis | Level 1 | Total other assets [Domain]
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	7,108	6,599
Recurring basis | Level 3
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	1,066	1,066
Total	1,066	1,066
Recurring basis | Level 3 | Auction-rate securities
Investments measured at fair value on a recurring basis
Other Assets, Fair Value Disclosure	$ 1,066	$ 1,066