Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Summary of Investments

Investments consist of the following as of June 30, 2018 and December 31, 2017 (dollars in thousands):

	June 30, 2018
			Gross Unrealized
	Cost		Gain		(Loss)			Fair Value
Short-term investments (available for sale):
Non-governmental debt securities	$	128,511	$	17	$	(336	)	$	128,192
Treasury and federal agencies		23,518		1		(140	)		23,379
Total short-term investments		152,029		18		(476	)		151,571
Restricted short-term investments (available for sale):
Non-governmental debt securities		4,570		-		-			4,570
Total investments (available for sale)	$	156,599	$	18	$	(476	)	$	156,141

	December 31, 2017
			Gross Unrealized
	Cost		Gain		(Loss)			Fair Value
Short-term investments (available for sale):
Municipal bonds	$	830	$	-	$	-		$	830
Non-governmental debt securities		125,485		7		(222	)		125,270
Treasury and federal agencies		30,211		-		(133	)		30,078
Total short-term investments		156,526		7		(355	)		156,178
Restricted short-term investments (available for sale):
Non-governmental debt securities		5,070		-		-			5,070
Total investments (available for sale)	$	161,596	$	7	$	(355	)	$	161,248

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 June 30, 2018 and December 31, 2017 were as follows (dollars in thousands):

	As of  June 30, 2018
	Level 1		Level 2		Level 3		Total
Non-governmental debt securities	$	15,000	$	117,762	$	-	$	132,762
Treasury and federal agencies		-		23,379		-		23,379
Totals	$	15,000	$	141,141	$	-	$	156,141
	As of  December 31, 2017
	Level 1		Level 2		Level 3		Total
Municipal bonds	$	-	$	830	$	-	$	830
Non-governmental debt securities		31,500		98,840		-		130,340
Treasury and federal agencies		-		30,078		-		30,078
Totals	$	31,500	$	129,748	$	-	$	161,248

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 paid to CCKF for the quarters and years to date ended June 30, 2018 and 2017 were as follows (dollars in thousands):

	Maintenance Fee Payments
For the quarter ended June 30, 2018	$	377
For the quarter ended June 30, 2017	$	332
For the year to date ended June 30, 2018	$	753
For the year to date ended June 30, 2017	$	657