Investments

3 Months Ended

Mar. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Investments

6. Investments

The amortized cost, unrealized gains and losses and fair value of investments available-for-sale as of March 31, 2015 are as follows:

	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value
Corporate bonds and notes – short-term	$	76,486,926	$	13,853	$	(11,916	)	$	76,488,863
Corporate bonds and notes – long-term		5,196,141		452		(2,757	)		5,193,836
US government and municipal obligations – long-term		2,003,445		—		(363	)		2,003,082
Total investments	$	83,686,512	$	14,305	$	(15,036	)	$	83,685,781

Short-term investments have maturities ranging from one and twelve months with a weighted average maturity of 4.7 months at March 31, 2015. Long-term investments have maturities ranging from April 2016 to June 2016 with a weighted average maturity of 13.7 months.

The amortized cost, unrealized gains and losses and fair value of investments available-for-sale as of December 31, 2014 are as follows:

	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value
Corporate bonds and notes – short-term	$	42,011,286	$	4,883	$	(13,387	)	$	42,002,782
Corporate bonds and notes – long-term		791,261		—		(2,493	)		788,768
Total investments	$	42,802,547	$	4,883	$	(15,880	)	$	42,791,550

Short-term investments have maturities ranging from one and twelve months with a weighted average maturity of 4.1 months at December 31, 2014. Long-term investments have maturities ranging from January 2016 to May 2016 with a weighted average maturity of 13.8 months.