MARKETABLE SECURITIES (Tables)

9 Months Ended

Mar. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Schedule of marketable securities

Marketable securities consisted of the following as of March 31, 2019 and June 30, 2018 (in thousands):

	March 31, 2019
			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		Losses			Value
Short-term available-for-sale securities:
U.S. treasury securities	$	123,149	$	—	$	(3	)	$	123,146
Commercial paper	110,478		—		—			110,478
Corporate bonds	61,713		60		—			61,773
Asset-backed securities	30,727		32		—			30,759
Mutual fund securities	296		—		—			296
	326,363		92		(3		)	326,452
Long-term available-for-sale securities:
Corporate bonds	32,421		44		—			32,465
Asset-backed securities	22,721		32		—			22,753
Mutual fund securities	790		—		—			790
	55,932		76		—			56,008
Total	$	382,295	$	168	$	(3	)	$	382,460

	June 30, 2018
			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		Losses			Value
Short-term available-for-sale securities:
U.S. treasury securities	$	297,965	$	—	$	(461	)	$	297,504
Mutual fund securities	235		—		—			235
	298,200		—		(461		)	297,739
Long-term available-for-sale securities:
Mutual fund securities	919		—		—			919
	919		—		—			919
Total	$	299,119	$	—	$	(461	)	$	298,658

Schedule of amortized cost and estimated fair value of available-for-sale securities by contractual maturity

As of March 31, 2019, the amortized cost and estimated fair value of available-for-sale debt securities by contractual maturity were as follows (in thousands):

	Amortized		Fair
	Cost		Value
Due in one year or less	$	326,067	$	326,156
Due in one to three years	55,142		55,218
Total	$	381,209	$	381,374