Investments

The Company classifies its short-term investments as “available-for-sale” and records such assets at the estimated fair value with unrealized gains and losses excluded from net loss and reported, net of tax, in comprehensive loss. When the investments are sold, such gain or loss will be transferred from accumulated other comprehensive loss to net realized gain on short-term investments and interest income, net on the Consolidated Statements of Operations. The portion of unrealized losses that are deemed to be other-than-temporary in nature are charged to the Consolidated Statements of Operations. The basis for computing realized and unrealized gains or losses is by specific identification. In addition, the Company had $1.1 million each in restricted cash related to its voluntary disability insurance as of March 31, 2015 and 2014, and these amounts are included in cash and cash equivalents on the Consolidated Balance Sheets.

The following is a summary of cash, cash equivalents and available-for-sale investments by type of instrument (in thousands):



	March 31, 2015									March 31, 2014
	Amortized Cost		Gross Unrealized					Estimated Fair Value		Amortized Cost		Gross Unrealized					Estimated Fair Value
	Amortized Cost		Gains		Losses			Estimated Fair Value		Amortized Cost		Gains		Losses			Estimated Fair Value
Cash	$	33,936	$	—	$	—		$	33,936	$	65,867	$	—	$	—		$	65,867
Cash equivalents	2,559		—		—			2,559		5,672		—		—			5,672
U.S. Treasury securities and agency bonds	1,230		—		—			1,230		2,838		—		—			2,838
Corporate bonds	10,772		28		(6		)	10,794		10,599		30		(2		)	10,627
Mortgage-backed and asset-backed securities*	—		15		—			15		1,793		297		(16		)	2,074
Mutual Funds	24,895		1,955		(59		)	26,791		14,373		2,392		(402		)	16,363
Preferred stock	11		22		—			33		2,406		736		—			3,142
	$	73,403	$	2,020	$	(65	)	$	75,358	$	103,548	$	3,455	$	(420	)	$	106,583
Reported as:
Cash and cash equivalents								$	36,495								$	71,539
Short-term investments available-for-sale								38,863									35,044
								$	75,358								$	106,583


*	At March 31, 2015 and 2014, zero and $1.1 million of the estimated fair value presented were mortgage-backed securities, respectively.

The established guidelines for measuring fair value and expanded disclosures regarding fair value measurements are defined as a three-level valuation hierarchy for disclosure of fair value measurements as follows:



Level 1 —		Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date.

Level 2 —		Inputs (other than quoted market prices included in Level 1) are either directly or indirectly observable for the asset or liability through correlation with market data at the measurement date and for the duration of the instrument’s anticipated life.

Level 3 —		Inputs reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. Consideration is given to the risk inherent in the valuation technique and the risk inherent in the inputs to the model. Valuation of instruments includes unobservable inputs to the valuation methodology that are significant to the measurement of the fair value of assets or liabilities.

The following is a summary of cash, cash equivalents and available-for-sale investments by type of instruments measured at fair value on a recurring basis (in thousands):



	March 31, 2015								March 31, 2014
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Cash	$	33,936	$	—	$	—	$	33,936	$	65,867	$	—	$	—	$	65,867
Cash equivalents	2,559		—		—		2,559		5,672		—		—		5,672
U.S. Treasury securities and agency bonds	1,230		—		—		1,230		2,838		—		—		2,838
Corporate bonds	—		10,794		—		10,794		—		10,627		—		10,627
Mortgage-backed and asset-backed securities	—		15		—		15		—		2,074		—		2,074
Mutual funds	26,791		—		—		26,791		16,363		—		—		16,363
Preferred stock	—		33		—		33		—		3,142		—		3,142
	$	64,516	$	10,842	$	—	$	75,358	$	90,740	$	15,843	$	—	$	106,583

There were no significant transfers in and out of Level 1 and Level 2 fair value measurements during the fiscal year ended March 31, 2015 and 2014.

The following is a summary of the cost and estimated fair values of available-for-sale securities with stated maturities, which include U.S. Treasury securities and agency bonds, corporate bonds and mortgage-backed and asset-backed securities, by contractual maturity (in thousands):



	March 31, 2015
	Cost		Estimated Fair Value
Less than 1 year	$	3,335	$	3,340
Mature in 1 – 2 years	7,965		7,979
Mature in 3 – 5 years	702		706
Mature after 5 years	—		14
	$	12,002	$	12,039

The following is a summary of gross unrealized losses (in thousands):



	Less Than 12 Months of Unrealized Losses					12 Months or More of Unrealized Losses					Total
As of March 31, 2015	Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses
U.S. Treasury securities and agency bonds	$	—	$	—		$	—	$	—		$	—	$	—
Corporate bonds	878		(6		)	—		—			878		(6		)
Mutual funds	14,592		(17		)	475		(42		)	15,067		(59		)
	$	15,470	$	(23	)	$	475	$	(42	)	$	15,945	$	(65	)



	Less Than 12 Months of Unrealized Losses					12 Months or More of Unrealized Losses					Total
As of March 31, 2014	Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses
U.S. Treasury securities and agency bonds	$	—	$	—		$	—	$	—		$	—	$	—
Corporate bonds	992		(2		)	—		—			992		(2		)
Mortgage-backed and asset-backed securities	431		(16		)	—		—			431		(16		)
Mutual funds	4,819		(333		)	405		(69		)	5,224		(402		)
	$	6,242	$	(351	)	$	405	$	(69	)	$	6,647	$	(420	)

Other-Than-Temporary Impairment

Based on an evaluation of securities that have been in a continuous loss position, the Company recognized other-than-temporary impairment charges for its short-term investments and marketable securities. During the fiscal years ended March 31, 2015 and 2014, the Company did not record any other-than-temporary impairment charges. During the fiscal year ended March 31, 2013, the Company recorded other-than-temporary impairment charges of $1.1 million. The Company considered various factors which included a credit and liquidity assessment of the underlying securities and the Company’s intent and ability to hold the underlying securities until the estimated date of recovery of its amortized cost.