The following tables summarize the Company’s cash and available-for-sale securities’ amortized cost, gross unrealized gains, gross unrealized losses, and fair value by significant investment category recorded as cash and cash equivalents, short-term, or long-term investments as of September 30, 2017 and March 31, 2017 (in thousands):



September 30, 2017	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Cash & Cash Equivalents		Short-term investments (due in 1 year or less)		Long-term investments (due in 1 to 3 years)
Cash	$	290,429	$	—	$	—		$	290,429	$	290,429	$	—	$	—
Level 1:
Mutual Funds	13,507		675		(27		)	14,155		—		14,155		—
US Treasury Notes	32,958		—		(66		)	32,892		—		20,084		12,808
Subtotal	46,465		675		(93		)	47,047		—		34,239		12,808
Level 2:
Government Agency Securities	47,851		—		(139		)	47,712		—		26,870		20,842
Commercial Paper	52,099		—		—			52,099		11,185		40,914		—
Corporate Bonds	146,781		126		(95		)	146,812		—		78,730		68,082
Certificates of Deposits ("CDs")	21,532		14		—			21,546		1,502		16,525		3,519
Subtotal	268,263		140		(234		)	268,169		12,687		163,039		92,443

Total cash, cash equivalents and investments measured at fair value	$	605,157	$	815	$	(327	)	$	605,645	$	303,116	$	197,278	$	105,251



March 31, 2017	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Cash & Cash Equivalents		Short-term investments (due in 1 year or less)		Long-term investments (due in 1 to 3 years)
Cash	$	295,877	$	—	$	—		$	295,877	$	295,877	$	—	$	—
Level 1:
Mutual Funds	12,079		352		(32		)	12,399		—		12,399		—
US Treasury Notes	35,960		—		(68		)	35,892		—		17,560		18,332
Subtotal	48,039		352		(100		)	48,291		—		29,959		18,332
Level 2:
Government Agency Securities	54,415		20		(164		)	54,271		—		15,309		38,962
Commercial Paper	47,152		—		—			47,152		6,093		41,059		—
Corporate Bonds	141,508		64		(224		)	141,348		—		73,676		67,672
Certificates of Deposits ("CDs")	20,383		3		—			20,386		—		18,176		2,210
Subtotal	263,458		87		(388		)	263,157		6,093		148,220		108,844

Total cash, cash equivalents and investments measured at fair value	$	607,374	$	439	$	(488	)	$	607,325	$	301,970	$	178,179	$	127,176