INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Schedule of Available-for-sale and Trading Securities Reconciliation

The following tables summarize our short-term investments (in thousands):

		As of December 31, 2015
	Maturity (in years)	Amortized cost		Gross unrealized gains		Gross unrealized losses			Estimated fair value
Corporate debt securities	1 year or less	$	27,644	$	—	$	(22	)	$	27,622
Commercial paper	1 year or less	45,158		54		—			45,212
		$	72,802	$	54	$	(22	)	$	72,834

		As of December 31, 2014
	Maturity (in years)	Amortized cost		Gross unrealized gains		Gross unrealized losses			Estimated fair value
Corporate debt securities	1 year or less	$	21,208	$	3	$	(1	)	$	21,210
Commercial paper	1 year or less	1,500		—		—			1,500
		$	22,708	$	3	$	(1	)	$	22,710