FAIR VALUE OF ASSETS AND LIABILITIES (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
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	$ 1,042	$ 1,036
Other assets	6,633	6,044
Total	9,801	9,767
Recurring basis | Corporate debt securities and other obligations
Investments measured at fair value on a recurring basis
Short-term investments		2,687
Recurring basis | Corporate equity securities
Investments measured at fair value on a recurring basis
Short-term investments	2,126
Recurring basis | Auction-rate securities
Investments measured at fair value on a recurring basis
Other assets	1,066	1,066
Recurring basis | Institutional money market funds
Investments measured at fair value on a recurring basis
Other assets	434	597
Recurring basis | Fixed income
Investments measured at fair value on a recurring basis
Other assets	1,042	902
Recurring basis | Marketable equity securities
Investments measured at fair value on a recurring basis
Other assets	4,091	3,479
Recurring basis | Total institutional funds - Deferred compensation plan
Investments measured at fair value on a recurring basis
Other assets		4,978
Recurring basis | Total Institutional Funds [Member]
Investments measured at fair value on a recurring basis
Other assets	5,567
Recurring basis | Level 1
Investments measured at fair value on a recurring basis
Money market funds	1,042	1,036
Other assets	5,567	4,978
Total	8,735	8,701
Recurring basis | Level 1 | Corporate equity securities
Investments measured at fair value on a recurring basis
Short-term investments	2,126	2,687
Recurring basis | Level 1 | Institutional money market funds
Investments measured at fair value on a recurring basis
Other assets	434	597
Recurring basis | Level 1 | Fixed income
Investments measured at fair value on a recurring basis
Other assets	1,042	902
Recurring basis | Level 1 | Marketable equity securities
Investments measured at fair value on a recurring basis
Other assets	4,091	3,479
Recurring basis | Level 1 | Total institutional funds - Deferred compensation plan
Investments measured at fair value on a recurring basis
Other assets		4,978
Recurring basis | Level 1 | Total Institutional Funds [Member]
Investments measured at fair value on a recurring basis
Other assets	5,567
Recurring basis | Level 2
Investments measured at fair value on a recurring basis
Total	0	0
Recurring basis | Level 2 | Corporate debt securities and other obligations
Investments measured at fair value on a recurring basis
Short-term investments		0
Recurring basis | Level 3
Investments measured at fair value on a recurring basis
Other assets	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	$ 1,066	$ 1,066