Investments (Tables)

9 Months Ended

Sep. 30, 2018

Investments

Schedule of Investments

At September 30, 2018, investments - debt securities and restricted investments classified as available-for-sale securities were as follows:

			Gross Unrealized		Gross Unrealized
	Amortized Cost		Gains		Losses		Fair Value
Investments - debt securities:
U.S. Treasury securities	$	9,996	$	—	$	2	$	9,994
Corporate debt securities		3,566		4		387		3,183
		13,562		4		389		13,177
Restricted investments:
Short-term bond		3,275		—		13		3,262
Money market fund		167		—		—		167
		3,442		—		13		3,429
	$	17,004	$	4	$	402	$	16,606

At December 31, 2017, investments - debt securities, investments - equity securities and restricted investments classified as available-for-sale securities were as follows:

			Gross Unrealized		Gross Unrealized
	Amortized Cost		Gains		Losses		Fair Value
Investments - debt securities:
U.S. Treasury securities	$	9,892	$	—	$	22	$	9,870
Corporate debt securities		67,781		411		1,817		66,375
		77,673		411		1,839		76,245
Investments - equity securities:
Preferred stock		35,955		423		1,355		35,023
Restricted investments:
Short-term bond		4,264		—		13		4,251
Money market fund		218		—		—		218
		4,482		—		13		4,469
	$	118,110	$	834	$	3,207	$	115,737

Schedule of Unrealized Loss Position and Related Fair Value of Investments

The following table provides the U.S. Treasury securities, corporate debt securities and restricted investments unrealized loss position and related fair values as of September 30, 2018:

	Less Than 12 Months				12 Months or Greater
			Unrealized				Unrealized
	Fair Value		Losses		Fair Value		Losses
Investments - debt securities:
U.S. Treasury securities	$	9,994	$	2	$	—	$	—
Corporate debt securities		—		—		2,405		387
Restricted investments:
Short-term bond		—		—		3,262		13
	$	9,994	$	2	$	5,667	$	400

The following table provides the U.S. Treasury securities, corporate debt securities, preferred stock and restricted investments unrealized loss position and related fair values as of December 31, 2017:

	Less Than 12 Months				12 Months or Greater
			Unrealized				Unrealized
	Fair Value		Losses		Fair Value		Losses
Investments - debt securities:
U.S. Treasury securities	$	9,870	$	22	$	—	$	—
Corporate debt securities		15,515		691		29,595		1,126
Investments - equity securities:
Preferred stock		11,263		1,337		1,986		18
Restricted investments:
Short-term bond		—		—		4,251		13
	$	36,648	$	2,050	$	35,832	$	1,157

Schedule of Contractual Maturities of Investments

	Amortized Cost		Fair Value
Due in one year or less	$	12,707	$	12,318
Due after one year through five years		785		785
Due after five years through ten years		70		74
		13,562		13,177
Restricted investments		3,442		3,429
	$	17,004	$	16,606