INVESTMENTS

The Company’s investments consist of corporate debt and U.S. Treasury notes classified as available-for-sale securities.

The Company limits the amount of investment exposure as to institution, maturity, and investment type. To mitigate credit risk, the Company invests in investment grade corporate debt and United States Treasury notes. Such securities are reported at fair value, with unrealized gains and losses excluded from earnings and shown separately as a component of accumulated other comprehensive loss within stockholders’ equity. Realized gains and losses are reclassified from other comprehensive loss to other income (expense) on the condensed consolidated statements of operations when incurred. The Company may pay a premium or receive a discount upon the purchase of available-for-sale securities. Interest earned and gains realized on available-for-sale securities and amortization of discounts received and accretion of premiums paid on the purchase of available-for-sale securities are included in investment income.

The following table is a summary of amortized cost, unrealized gain and loss, and the fair value of available-for-sale securities as of June 30, 2017 and December 31, 2016 (in thousands):



	June 30, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Investments:
Corporate debt	$	43,185	$	1	$	(66	)	$	43,120
U.S. Treasury notes	68,309		—		(118		)	68,191
Total	$	111,494	$	1	$	(184	)	$	111,311
Reported as:
Short-term investments	$	94,891	$	1	$	(167	)	$	94,725
Long-term investments	16,603		—		(17		)	16,586
Total	$	111,494	$	1	$	(184	)	$	111,311



	December 31, 2016
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Investments:
Corporate debt	$	51,354	$	—	$	(121	)	$	51,233
U.S. Treasury notes	61,048		5		(77		)	60,976
Total	$	112,402	$	5	$	(198	)	$	112,209
Reported as:
Short-term investments	$	90,050	$	1	$	(134	)	$	89,917
Long-term investments	22,352		4		(64		)	22,292
Total	$	112,402	$	5	$	(198	)	$	112,209

Short-term and long-term investments include accrued interest of $0.4 million and $0.1 million, respectively, as of June 30, 2017. Short-term and long-term investments includes accrued interest of $0.3 million and $0.1 million, respectively, as of December 31, 2016. The Company has not incurred any realized gains or losses on investments for the three and six months ended June 30, 2017 and 2016. Investments are classified as short-term or long-term depending on the underlying investment’s maturity date. Long-term investments held by the Company have a maturity date range of greater than 12 months and a maximum of 15 months as of June 30, 2017.