Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2020

Schedule of cash and available-for-sale securities

The following tables summarize our cash and available-for-sale securities that were measured at fair value by significant investment category within the fair value hierarchy (in thousands):


	September 30, 2020
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Fair Value		Cash and Cash Equivalents		Short-Term Marketable Securities		Cash- Restricted
Assets:
Cash-unrestricted	$	49,144	$	—	$	—	$	49,144	$	49,144	$	—	$	—
Cash-restricted	1,015		—		—		1,015		—		—		1,015
Total cash	$	50,159	$	—	$	—	$	50,159	$	49,144	$	—	$	1,015
Available-for-sale:
Level I:
Money market funds	$	23,201	$	—	$	—	$	23,201	$	23,201	$	—	$	—


Total	$	73,360	$	—	$	—	$	73,360	$	72,345	$	—	$	1,015

	December 31, 2019
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Fair Value		Cash and Cash Equivalents		Short-Term Marketable Securities		Cash- Restricted
Assets:
Cash-unrestricted	$	16,614	$	—	$	—	$	16,614	$	16,614	$	—	$	—
Cash-restricted	2,075		—		—		2,075		—		—		2,075
Total cash	$	18,689	$	—	$	—	$	18,689	$	16,614	$	—	$	2,075
Available-for-sale:
Level I:
Money market funds	$	5,047	$	—	$	—	$	5,047	$	5,047	$	—	$	—
US treasury securities	36,942		36		—		36,978		—		36,978		—
Subtotal	$	41,989	$	36	$	—	$	42,025	$	5,047	$	36,978	$	—
Total	$	60,678	$	36	$	—	$	60,714	$	21,661	$	36,978	$	2,075

Schedule of debt

The carrying values of the components of the 2014 Notes and the 2019 Notes are as follows (in thousands):



	September 30, 2020		December 31, 2019
2.75% 2014 Notes due 2034
Principal amount	$	1,079	$	1,079
Unamortized debt discount	(17)		(18)
Unamortized debt issuance cost	(4)		(4)
	$	1,058	$	1,057







5.25% 2019 Notes due 2024
Principal amount	$	55,000	$	55,000


Unamortized debt issuance cost	(1,937)		(2,236)
	$	53,063	$	52,764
Net carrying value of all Notes	$	54,121	$	53,821

The following table summarizes the par value, carrying value and the estimated fair value of the 2014 and 2019 Notes at September 30, 2020 and December 31, 2019, respectively (in thousands):


	September 30, 2020						December 31, 2019
	Par Value		Carrying Value		Fair Value		Par Value		Carrying Value		Fair Value
2014 Notes	$	1,079	$	1,058	$	1,122	$	1,079	$	1,057	$	1,122
2019 Notes	55,000		53,063		143,039		55,000		52,764		73,975
Total	$	56,079	$	54,121	$	144,161	$	56,079	$	53,821	$	75,097