Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Summary of Investments

Investments consist of the following as of December 31, 2019 and 2018 (dollars in thousands):

	December 31, 2019
			Gross Unrealized
	Cost		Gain		(Loss)			Fair Value
Short-term investments (available for sale):
Municipal bonds	$	1,361	$	3	$	-		$	1,364
Non-governmental debt securities		165,423		433		(37	)		165,819
Treasury and federal agencies		18,307		7		(9	)		18,305
Total short-term investments (available for sale)	$	185,091	$	443	$	(46	)	$	185,488

	December 31, 2018
			Gross Unrealized
	Cost		Gain		(Loss)			Fair Value
Short-term investments (available for sale):
Non-governmental debt securities	$	179,393	$	35	$	(337	)	$	179,091
Treasury and federal agencies		17,417		5		(85	)		17,337
Total short-term investments (available for sale)	$	196,810	$	40	$	(422	)	$	196,428

Schedule of Available-for-Sale Investments

A schedule of available-for-sale investments segregated by their original stated terms to maturity as of December 31, 2019 and 2018 are as follows (dollars in thousands): 

	Less than one year		One to five years		Six to ten years		Greater than ten years		Total
Original stated term to maturity of available-for-sale-    investments as of December 31, 2019	$	125,087	$	59,751	$	-	$	650	$	185,488
Original stated term to maturity of available-for-sale-    investments as of December 31, 2018	$	156,657	$	38,845	$	-	$	926	$	196,428

Investments Measured at Fair Value on Recurring Basis

Investments measured at fair value on a recurring basis subject to the disclosure requirements of FASB ASC Topic 820 – Fair Value Measurements at December 31, 2019 and 2018 were as follows (dollars in thousands):

	As of December 31, 2019
	Level 1		Level 2		Level 3		Total
Municipal bonds	$	-	$	1,364	$	-	$	1,364
Non-governmental debt securities		-		165,819		-		165,819
Treasury and federal agencies		-		18,305		-		18,305
Totals	$	-	$	185,488	$	-	$	185,488

	As of December 31, 2018
	Level 1		Level 2		Level 3		Total
Non-governmental debt securities	$	20,000	$	159,091	$	-	$	179,091
Treasury and federal agencies		-		17,337		-		17,337
Totals	$	20,000	$	176,428	$	-	$	196,428

Schedule of Maintenance Fee Payment to CCKF

We make periodic operating maintenance payments related to proprietary rights that we use in our intellipath^® personalized learning technology. The total fees recorded for the years ended December 31, 2019, 2018 and 2017 were as follows (dollars in thousands):

	Maintenance Fee Payments
For the year ended December 31, 2019	$	1,418
For the year ended December 31, 2018	$	1,462
For the year ended December 31, 2017	$	1,371