Investments (Tables)

9 Months Ended

Sep. 30, 2016

Available For Sale Securities [Abstract]

Amortized Cost and Fair Value on Available-for-Sale Investments and Unrealized Gains and Losses

The amortized cost and fair value on the available-for-sale investments and unrealized gains and losses as of September 30, 2016 and December 31, 2015 were as follows (in thousands):

	As of  September 30, 2016
	Amortized		Gross Unrealized		Gross Unrealized			Fair
	Cost		Gains		Losses			Value
Amounts maturing in one year or less
Corporate notes and obligations	$	8,421	$	1	$	(4	)	$	8,418
U.S. agency securities		2,400		—		—			2,400
Total available-for-sale debt securities	$	10,821	$	1	$	(4	)	$	10,818

	As of  December 31, 2015
	Amortized		Gross Unrealized		Gross Unrealized			Fair
	Cost		Gains		Losses			Value
Amounts maturing in one year or less
Corporate notes and obligations	$	2,245	$	—	$	—		$	2,245
U.S. agency securities		3,016		—		(1	)		3,015
U.S. government treasury securities		999		1		—			1,000
Total available-for-sale debt securities	$	6,260	$	1	$	(1	)	$	6,260