Investments (Tables)

3 Months Ended

Mar. 31, 2017

Investments, Debt and Equity Securities [Abstract]

Schedule of Investments

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

	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Fair Value
Investments:
Corporate debt securities	$	128,200	$	6,005	$	1,420	$	132,785
Preferred stock	40,525		876		335		41,066
Common stock	1,662		110		—		1,772
	170,387		6,991		1,755		175,623
Restricted investments:
Short-term bond	4,235		4		—		4,239
Money market fund	209		—		—		209
	4,444		4		—		4,448
	$	174,831	$	6,995	$	1,755	$	180,071

At December 31, 2016, investments and restricted investments classified as available-for-sale securities were as follows:

	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Fair Value
Investments:
Corporate debt securities	$	135,590	$	5,311	$	1,769	$	139,132
Preferred stock	36,048		656		111		36,593
	171,638		5,967		1,880		175,725
Restricted investments:
Short-term bond	4,232		—		6		4,226
Money market fund	1,410		—		—		1,410
	5,642		—		6		5,636
	$	177,280	$	5,967	$	1,886	$	181,361

Continuous Unrealized Loss Position

The following table provides the debt securities, preferred stock and restricted investments unrealized loss position and related fair values:

	As of March 31, 2017								As of December 31, 2016
	Less Than 12 Months				12 Months or Greater				Less Than 12 Months				12 Months or Greater
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Investments:
Corporate debt securities	$	45,034	$	480	$	8,462	$	940	$	64,516	$	1,410	$	6,971	$	359
Preferred stock	7,447		272		132		63		—		—		153		111
Restricted investments:
Short-term bond	—		—		—		—		4,226		6		—		—
	$	52,481	$	752	$	8,594	$	1,003	$	68,742	$	1,416	$	7,124	$	470

Contractual Maturities of Investments

The net carrying value and estimated fair value of investments and restricted investments classified as available-for-sale at March 31, 2017, by contractual maturity are shown in the following table. Actual maturities may differ from contractual maturities because certain borrowers have the right to call or prepay obligations.

	Amortized Cost		Fair Value
Due in one year or less	$	3,932	$	3,470
Due after one year through five years	124,177		129,266
Due after ten years through fifteen years	91		49
	128,200		132,785
Preferred stock	40,525		41,066
Common stock	1,662		1,772
Restricted investments	4,444		4,448
	$	174,831	$	180,071