FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Jun. 30, 2019

Fair Value Disclosures [Abstract]

Fair Value Measurements

Cash, cash equivalents, and available-for-sale investments (in thousands):

	Amortized		Gross Unrealized		Gross Unrealized			Estimated		Cash and Cash		Short-Term		Long-Term
As of June 30, 2019	Costs		Gain		Loss			Fair Value		Equivalents		Investments		Investments
Cash	$	23,533	$	—	$	—		$	23,533	$	23,533	$	—	$	—
Level 1:
Money market funds	240,905		—		—			240,905		240,905		—		—
Treasury securities	2,910		2		—			2,912		—		—		2,912
Subtotal	267,348		2		—			267,350		264,438		—		2,912
Level 2:
Corporate bonds	40,128		122		(3		)	40,247		—		23,613		16,634
Commercial paper	6,176		—		(2		)	6,174		4,587		1,587		—
Municipal securities	2,098		23		—			2,121		—		—		2,121
Agency bond	2,289		—		(3		)	2,286		—		2,286		—
Subtotal	50,691		145		(8		)	50,828		4,587		27,486		18,755
Total assets	$	318,039	$	147	$	(8	)	$	318,178	$	269,025	$	27,486	$	21,667

	Amortized		Gross Unrealized		Gross Unrealized			Estimated		Cash and Cash		Short-Term
As of March 31, 2019	Costs		Gain		Loss			Fair Value		Equivalents		Investments
Cash	$	25,364	$	—	$	—		$	25,364	$	25,364	$	—
Level 1:
Money market funds	251,219		—		—			251,219		251,219		—
Subtotal	276,583		—		—			276,583		276,583		—
Level 2:
Corporate debt	46,516		51		(29		)	46,538		—		46,538
Municipal securities	5,511		17		—			5,528		—		5,528
Asset backed securities	13,596		9		(17		)	13,588		—		13,588
Agency bond	4,260		—		(15		)	4,245		—		4,245
Subtotal	69,883		77		(61		)	69,899		—		69,899
Total assets	$	346,466	$	77	$	(61	)	$	346,482	$	276,583	$	69,899

Contractual Maturity of Investments

Contractual maturities of investments as of June 30, 2019 are set forth below (in thousands):

	Estimated
	Fair Value
Due within one year	$	27,486
Due after one year	21,667
Total	$	49,153