4. MARKETABLE SECURITIES

The Company invests its excess cash in fixed income instruments denominated and payable in U.S. dollars, including money market accounts, commercial paper, asset-backed securities, and corporate obligations, in accordance with the Company’s investment policy that primarily seeks to maintain adequate liquidity and preserve capital.

As of March 31, 2017 and December 31, 2016, the Company’s investment portfolio consisted of marketable securities with an original maturity of greater than 90 days. The Company has designated all investments as available-for-sale and therefore such investments are reported at fair value. Unrealized losses on marketable securities are recorded in accumulated other comprehensive loss, a component of stockholders’ equity, on the balance sheet.

The following table summarizes the Company’s investments in marketable securities by category as of March 31, 2017 and December 31, 2016:


(In thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
March 31, 2017
Current (due within 1 year or less)
Commercial paper		6,484		—		—		6,484
Corporate obligations		5,167		—		(2)		5,165
Noncurrent (due after 1 year)
Asset backed security		751		—		—		751
Total	$	12,402	$	—	$	(2)	$	12,400

December 31, 2016
Current (due within 1 year or less)
Commercial paper		4,240		—		—		4,240
Corporate obligations		7,337		—		—		7,337
Total	$	11,577	$	—	$	—	$	11,577