Cash Equivalents and Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2016

Investments Debt And Equity Securities [Abstract]

Schedule of Estimated Fair Value of Cash Equivalents and Marketable Securities

The following tables summarize the estimated fair value of our cash equivalents and marketable securities and the gross unrealized gains and losses (in thousands):

	December 31, 2016
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Cash equivalents:
Money market funds	$	4,584	$	—	$	—		$	4,584
Reverse repurchase agreements		39,250		—		—			39,250
Total cash equivalents		43,834		—		—			43,834
Marketable securities:
US government and agency securities		15,758		—		(4	)		15,754
Total marketable securities	$	15,758	$	—	$	(4	)	$	15,754

	December 31, 2015
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Cash equivalents:
Money market funds	$	3,988	$	—	$	—		$	3,988
Reverse repurchase agreements		16,250		—		—			16,250
Total cash equivalents		20,238		—		—			20,238
Marketable securities:
US government and agency securities		3,769		—		(1	)		3,768
Total marketable securities	$	3,769	$	—	$	(1	)	$	3,768