Investments (Tables)

12 Months Ended

Dec. 31, 2019

Investments

Schedule of Investments

Investments classified as available-for-sale securities were as follows:

	December 31, 2019
			Gross Unrealized		Gross Unrealized
	Amortized Cost		Gains		(Losses)		Fair Value
Investments - debt securities:
Corporate debt securities	$	178	$	—	$	(125)	$	53
		178		—		(125)		53
Restricted investments:
Short-term bond		2,239		11		—		2,250
Money market fund		114		—		—		114
		2,353		11		—		2,364
	$	2,531	$	11	$	(125)	$	2,417

	December 31, 2018
			Gross Unrealized		Gross Unrealized
	Amortized Cost		Gains		(Losses)		Fair Value
Investments - debt securities:
U.S. Treasury Bills	$	6,936	$	1	$	—	$	6,937
Corporate debt securities		2,908		—		(887)		2,021
		9,844		1		(887)		8,958
Restricted investments:
Short-term bond		3,274		—		(9)		3,265
Money market fund		167		—		—		167
		3,441		—		(9)		3,432
	$	13,285	$	1	$	(896)	$	12,390

Schedule of Unrealized Loss Position and Related Fair Value of Investments

The following table provides the available-for-sale investments unrealized loss position and related fair values:

	December 31, 2019
	Less Than 12 Months				12 Months or Greater
			Unrealized				Unrealized
	Fair Value		Losses		Fair Value		Losses
Investments - debt securities:
Corporate debt securities	$	—	$	—	$	53	$	125

	December 31, 2018
	Less Than 12 Months				12 Months or Greater
			Unrealized				Unrealized
	Fair Value		Losses		Fair Value		Losses
Investments - debt securities:
Corporate debt securities	$	—	$	—	$	1,843	$	887
Restricted investments:
Short-term bond		—		—		3,265		9
	$	—	$	—	$	5,108	$	896

Schedule of Contractual Maturities of Investments

	December 31, 2019
	Amortized Cost		Fair Value
Due in one year or less	$	178	$	53
Restricted investments		2,353		2,364
	$	2,531	$	2,417