CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS (Tables)

3 Months Ended

Mar. 31, 2013

CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS [Abstract]

Summary of Cash Equivalents and Short-term Investments

The following is a summary of cash equivalents and short-term investments by type of instrument at March 31, 2013 and December 31, 2012 (in thousands):

	March 31, 2013
	Amortized		Gross Unrealized					Fair
	Cost		Gains		Losses			Value
Money market funds	$	6,524	$	—	$	—		$	6,524
Commercial paper		11,186		—		—			11,186
U.S. agency securities		57,509		16		—			57,525
Corporate bonds		30,987		—		(14	)		30,973
Total investments	$	106,206	$	16	$	(14	)	$	106,208
Reported as:
Cash equivalents	$	6,524	$	—	$	—		$	6,524
Short-term investments		99,682		16		(14	)		99,684
Total investments	$	106,206	$	16	$	(14	)	$	106,208

	December 31, 2012
	Amortized		Gross Unrealized					Fair
	Cost		Gains		Losses			Value
Money market funds	$	13,505	$	-	$	-		$	13,505
Commercial paper		9,696		-		-			9,696
U.S. agency securities		51,276		18		-			51,294
Corporate bonds		34,751		5		(5	)		34,751
U.S. Government bonds		5,019		2		-			5,021
Total investments	$	114,247	$	25	$	(5	)	$	114,267
Reported as:
Cash equivalents	$	13,505	$	-	$	-		$	13,505
Short-term investments		100,742		25		(5	)		100,762
Total	$	114,247	$	25	$	(5	)	$	114,267