Cash Equivalents and Investments

6 Months Ended

Jun. 30, 2019

Investments, Debt and Equity Securities [Abstract]

Cash Equivalents and Investments

Cash Equivalents and Investments

Marketable debt securities are classified as available-for-sale and carried at fair value in the accompanying consolidated balance sheets on a settlement date basis. The following tables summarize the gross unrealized gains and losses of the Company’s marketable securities as of June 30, 2019 and December 31, 2018:

	June 30, 2019
			Gross Unrealized
(In thousands)	Amortized Cost		Gains		Losses		Fair Value
Money market funds	$	4,831	$	—	$	—	$	4,831
Commercial paper	17,149		—		—		17,149
Corporate notes	17,225		20		—		17,245
U.S. government securities	6,955		11		—		6,966
U.S. asset-backed securities	10,680		7		—		10,687
	$	56,840	$	38	$	—	$	56,878
Classified as:
Cash equivalents							$	4,831
Short-term investments							52,047
							$	56,878

	December 31, 2018
			Gross Unrealized
(In thousands)	Amortized Cost		Gains		Losses			Fair Value
Money market funds	$	5,838	$	—	$	—		$	5,838
Repurchase agreements	5,000		—		—			5,000
Commercial paper	30,710		—		—			30,710
Corporate notes	13,168		—		(24		)	13,144
U.S. government securities	10,167		—		(1		)	10,166
U.S. asset-backed securities	10,632		—		(14		)	10,618
	$	75,515	$	—	$	(39	)	$	75,476
Classified as:
Cash equivalents								$	10,838
Short-term investments								64,638
								$	75,476

At December 31, 2018, the Company invested $5.0 million in overnight repurchase agreement securities classified as cash equivalents on the balance sheet. As of June 30, 2019, no amounts were invested in overnight repurchase agreements.

There were no marketable securities that the Company considers to be other-than-temporarily impaired as of June 30, 2019. The Company's investment strategy is to buy short-duration marketable securities with a high credit rating. As of June 30, 2019, all marketable securities held by the Company had remaining contractual maturities of one year or less.

If any adjustment to fair value reflects a decline in the value of the investment, the Company considers all available evidence to evaluate the extent to which the decline is “other than temporary,” including the Company's intention to sell and, if so, mark the investment to market through a charge to our consolidated statements of operations. There have been no impairments of the Company’s assets measured and carried at fair value during the six months ended June 30, 2019.