BALANCE SHEET COMPONENTS - Property and Equipment, Net (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2017 |
|
| Property and Equipment, Net [Abstract] | |||
| Property and Equipment, Gross | $ 48,811 | $ 42,464 | |
| Less: Accumulated depreciation | (35,193) | (28,136) | |
| Property and Equipment, net | 13,618 | 14,328 | |
| Depreciation expense | 7,500 | 7,200 | $ 6,800 |
| Testing equipment | |||
| Property and Equipment, Net [Abstract] | |||
| Property and Equipment, Gross | 10,258 | 8,577 | |
| Computer and other equipment | |||
| Property and Equipment, Net [Abstract] | |||
| Property and Equipment, Gross | 7,264 | 6,265 | |
| Tooling equipment | |||
| Property and Equipment, Net [Abstract] | |||
| Property and Equipment, Gross | 10,624 | 9,594 | |
| Furniture and fixtures | |||
| Property and Equipment, Net [Abstract] | |||
| Property and Equipment, Gross | 2,083 | 1,890 | |
| Leasehold improvements | |||
| Property and Equipment, Net [Abstract] | |||
| Property and Equipment, Gross | 11,712 | 10,106 | |
| Software | |||
| Property and Equipment, Net [Abstract] | |||
| Property and Equipment, Gross | $ 6,870 | $ 6,032 | |