FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2014

Fair Value Disclosures [Abstract]

Summary of Valuation of Investments and Financial Instruments Pricing Levels

The following table summarizes the valuation of our investments and financial instruments by the above pricing levels as of the valuation dates listed:

			March 31, 2014
	Total		(Level 1)		(Level 2)
Investments:
Money Market Mutual Funds	$	77,130	$	77,130	$	—
Municipal bonds and notes		1,502		—		1,502
Corporate bonds and notes		77,526		—		77,526
		156,158		77,130		79,028
Deferred compensation plan assets		2,271		2,271		—
Total	$	158,429	$	79,401	$	79,028
			December 31, 2013
	Total		(Level 1)		(Level 2)
Short-term investments:
Money Market Mutual Funds	$	18,470	$	18,470	$	—
Commercial Paper		2,999		—		2,999
Municipal bonds and notes		1,499		—		1,499
Corporate bonds and notes		77,633		—		77,633
		100,601		18,470		82,131
Deferred compensation plan assets		2,109		2,109		—
Total	$	102,710	$	20,579	$	82,131