BALANCE SHEET COMPONENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash and cash equivalents:
Cash and cash equivalents	$ 96,035	$ 132,653
Restricted cash	3,390	2,998
Cash, cash equivalents and restricted cash	99,425	135,651	$ 138,478
Inventories:
Finished goods	6,142	11,171
Raw materials	1,249	1,145
Reserve for obsolescence	(987)	(151)
Inventories, net	6,404	12,165
Property and equipment:
Office equipment	578	537
Office software	1,037	918
Machinery	28	29
Furniture and fixtures	327	319
Leasehold improvements	1,001	1,022
Construction in progress (including internal-use software development costs)	0	19
Property and equipment, at cost	2,971	2,844
Accumulated depreciation and amortization	(2,236)	(1,910)
Property and equipment, net	735	934
Other accrued expenses:
Sales returns	373	801
Employee-related expense	1,258	4,051
Warehousing, inventory-related and other	756	1,269
Other accrued expenses	2,387	6,121
Deferred revenue:
Deferred revenue	4,506	6,795
China
Cash and cash equivalents:
Cash and cash equivalents	9,100
Unshipped product
Deferred revenue:
Deferred revenue	2,390	4,574
Auto ship advances
Deferred revenue:
Deferred revenue	1,985	1,876
Other
Deferred revenue:
Deferred revenue	131	345
Cash
Cash and cash equivalents:
Cash and cash equivalents	13,720	47,323
Cash equivalents
Cash and cash equivalents:
Cash and cash equivalents	$ 82,315	$ 85,330