Financial Instruments

3 Months Ended

Mar. 31, 2019

5. Financial Instruments

The Company elected to invest a portion of its cash assets in conservative, income earning, and liquid investments. Cash equivalents and investments, all of which are classified as available-for-sale securities, consisted of the following:


	March 31, 2019								December 31, 2018
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Estimated Fair Value		Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Estimated Fair Value
	(in thousands)
Money market deposits	$	588	$	—	$	—	$	588	$	26,539	$	—	$	—	$	26,539
U.S. Treasury securities		57,857		62		(287)		57,632		76,061		29		(405)		75,685
U.S. agency securities		13,010		—		(72)		12,938		13,017		—		(126)		12,891
Municipal securities		23,204		55		(24)		23,235		18,935		7		(57)		18,885
Total	$	94,659	$	117	$	(383)	$	94,393	$	134,552	$	36	$	(588)	$	134,000

Classified as:
Cash equivalents							$	588							$	26,539
Short-term investments								93,805								107,461
Total							$	94,393							$	134,000

The Company invests in U.S. Treasuries, U.S. agency and high quality municipal bonds which mature at par value and are all paying their coupons on schedule. The Company has therefore concluded there is currently no other than temporary impairment of its investments and will continue to recognize unrealized gains and losses in other comprehensive income (loss). During the three months ended March 31, 2019, there were no sales of investments, and during the three months ended March 31, 2018, the amount of gross realized gains and realized losses upon sales of investments were insignificant. The Company uses the specific investment identification method to calculate realized gains and losses and amounts reclassified out of other comprehensive income to net income. As of March 31, 2019, the Company had 12 investments in an unrealized loss position in its portfolio.

The following table summarizes the Company’s portfolio of available-for-sale securities by contractual maturity as of March 31, 2019:


	March 31, 2019
	Amortized Cost		Fair Value
	(in thousands)
Less than one year	$	57,974	$	57,910
Greater than one year but less than five years		36,097		35,895
Total	$	94,071	$	93,805