INVESTMENTS (Tables)

6 Months Ended

Jun. 30, 2013

Investments [Abstract]

Components of available-for-sale securities

Available-for-sale securities consisted of the following as of June 30, 2013 (in thousands):

	Amortized Cost		Gains in Accumulated Other Comprehensive Income		Losses in Accumulated Other Comprehensive Income			Estimated Fair Value
Current:
Money Market funds	$	19,125	$	—	$	—		$	19,125
Non-government sponsored debt securities	5,498		—		(2		)	5,496
Total current securities	24,623		—		(2		)	24,621
Noncurrent:
Non-government sponsored debt securities	—		—		—			—
Total noncurrent securities	—		—		—			—
Total available-for-sale securities	$	24,623	$	—	$	(2	)	$	24,621

Available-for-sale securities consisted of the following as of December 31, 2012 (in thousands):

	Amortized Cost		Gains in Accumulated Other Comprehensive Income		Losses in Accumulated Other Comprehensive Income		Estimated Fair Value
Current:
Money Market funds	$	16,987	$	—	$	—	$	16,987
Non-government sponsored debt securities	13,602		5		—		13,607
Total current securities	30,589		5		—		30,594
Noncurrent:
Non-government sponsored debt securities	3,000		—		—		3,000
Total noncurrent securities	3,000		—		—		3,000
Total available-for-sale securities	$	33,589	$	5	$	—	$	33,594

Estimated fair value of available-for-sale debt securities, by contractual maturity

The estimated fair value of available-for-sale debt securities at June 30, 2013 and December 31, 2012, by contractual maturity, was as follows (in thousands):

	Estimated Fair Value
	June 30, 2013		December 31, 2012
Due in one year or less	$	5,496	$	13,607
Due after one year through two years	—		3,000
	$	5,496	$	16,607