BALANCE SHEET COMPONENTS - Other Current Liabilities (Details) - USD ($)
$ in Thousands
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2017
Condensed Balance Sheet Statements, Captions [Line Items]      
Accrued expense $ 14,203 $ 18,241  
Accrued compensation and benefits 3,866 3,091  
Warranty accrual 4,518 3,840 $ 3,601
Deferred revenue and customer deposits 15,338 8,509  
Reserve for sales returns 783 1,219  
Other payables 42,543 32,943  
Total accrued liabilities 84,233 68,613  
Customer deposits      
Condensed Balance Sheet Statements, Captions [Line Items]      
Deferred revenue and customer deposits $ 2,982 $ 770