Short-Term Investments - Schedule of Short-Term Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized cost	$ 135,822	$ 123,395
Short-term investments, Gross unrealized gains	352	590
Short-term investments, Gross unrealized losses	(3)	(11)
Short-term investments	136,171	123,974
U.S. Treasury Securities
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized cost	45,007	28,281
Short-term investments, Gross unrealized gains	49	88
Short-term investments, Gross unrealized losses	(2)	(1)
Short-term investments	45,054	28,368
Corporate Bonds
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized cost	69,360	70,781
Short-term investments, Gross unrealized gains	214	360
Short-term investments, Gross unrealized losses	(1)	(10)
Short-term investments	69,573	71,131
Asset-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Short-term investments, Amortized cost	21,455	24,333
Short-term investments, Gross unrealized gains	89	142
Short-term investments	$ 21,544	$ 24,475