Income Taxes - Significant Components of Deferred Tax Assets and (Liabilities) (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 30,077	$ 20,526
Tax credit carryforwards	29,557	25,501
Lease liabilities - operating	1,314
Accruals and other	3,644	3,513
Depreciation and amortization	317	238
Gross deferred tax assets	64,909	49,778
Deferred tax asset valuation allowance	(64,032)	$ (49,778)
Total deferred tax assets, net of valuation allowance	877
Deferred tax liabilities:
Right-of-use assets - operating leases	(877)
Total deferred tax liabilities	(877)
Net deferred tax asset (liability)