Investments

3 Months Ended

Mar. 31, 2021

Investments Debt And Equity Securities [Abstract]

Investments

4. Investments

Investments by security type consisted of the following at March 31, 2021 and December 31, 2020 (in thousands):

	March 31, 2021
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
Investments:
Commercial paper	$	14,491	$	—	$	—		$	14,491
Corporate bonds		78,337		5		(42	)		78,300
Certificate of deposit		2,272		—		—			2,272
Government securities		110,885		27		(5	)		110,907
	$	205,985	$	32	$	(47	)	$	205,970

	December 31, 2020
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss			Fair Value
Investments:
Commercial paper	$	12,343	$	—	$	—		$	12,343
Corporate bonds		68,333		8		(52	)		68,289
Certificate of deposits		2,272		-		-			2,272
Government securities		104,491		6		(9	)		104,488
	$	187,439	$	14	$	(61	)	$	187,392

Investments with original maturities of less than 90 days are included in cash and cash equivalents on the condensed consolidated balance sheets and are not included in the table above. Investments with maturities of less than 12 months are considered current and those investments with maturities greater than 12 months are considered non-current assets.

Excluded from the table above is a restricted investment of $1,400 as the cost approximates current fair value.

The amortized cost and fair value of investments in commercial paper, corporate bonds, certificate of deposits and government securities by contractual maturity, as of March 31, 2021 were as follows (in thousands):

	Available-for-Sale as of March 31, 2021				Available-for-Sale as of December 31, 2020
	Cost		Fair Value		Cost		Fair Value
Due in 1-year or less	$	176,213	$	176,221	$	137,588	$	137,567
Due after 1-year through 5-years		29,772		29,749		49,851		49,825
	$	205,985	$	205,970	$	187,439	$	187,392