| Supplemental Balance Sheet Disclosures [Text Block] | 
    4.     BALANCE SHEET COMPONENTS 
     
   The components of certain balance sheet amounts are as follows (in thousands): 
     
    
|   | 
  | 
  December 31,   | 
  | 
 
|   | 
  | 
  2020   | 
  | 
  | 
  2019   | 
  | 
 
|   Cash and cash equivalents:   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
| Cash | 
  | 
$ | 
23,977 | 
  | 
  | 
$ | 
13,720 | 
  | 
 
| Cash equivalents | 
  | 
  | 
68,390 | 
  | 
  | 
  | 
82,315 | 
  | 
 
|   | 
  | 
  | 
92,367 | 
  | 
  | 
  | 
96,035 | 
  | 
 
| Restricted cash | 
  | 
  | 
525 | 
  | 
  | 
  | 
3,390 | 
  | 
 
|   | 
  | 
$ | 
92,892 | 
  | 
  | 
$ | 
99,425 | 
  | 
 
|   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
|   Inventories:   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
| Finished goods | 
  | 
$ | 
3,071 | 
  | 
  | 
$ | 
6,142 | 
  | 
 
| Raw materials | 
  | 
  | 
1,047 | 
  | 
  | 
  | 
1,249 | 
  | 
 
| Reserve for obsolescence | 
  | 
  | 
(339 | 
) | 
  | 
  | 
(987 | 
) | 
 
|   | 
  | 
$ | 
3,779 | 
  | 
  | 
$ | 
6,404 | 
  | 
 
|   Property and equipment:   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
| Office equipment | 
  | 
$ | 
449 | 
  | 
  | 
$ | 
578 | 
  | 
 
| Office software | 
  | 
  | 
1,001 | 
  | 
  | 
  | 
1,037 | 
  | 
 
| Machinery | 
  | 
  | 
30 | 
  | 
  | 
  | 
28 | 
  | 
 
| Furniture and fixtures | 
  | 
  | 
254 | 
  | 
  | 
  | 
327 | 
  | 
 
| Leasehold improvements | 
  | 
  | 
839 | 
  | 
  | 
  | 
1,001 | 
  | 
 
| Construction in progress | 
  | 
  | 
41 | 
  | 
  | 
  | 
— | 
  | 
 
|   Property and equipment, at cost   | 
  | 
  | 
2,614 | 
  | 
  | 
  | 
2,971 | 
  | 
 
| Accumulated depreciation and amortization | 
  | 
  | 
(2,075 | 
) | 
  | 
  | 
(2,236 | 
) | 
 
|   | 
  | 
$ | 
539 | 
  | 
  | 
$ | 
735 | 
  | 
 
|   Other accrued expenses:   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
| Sales returns | 
  | 
$ | 
189 | 
  | 
  | 
$ | 
373 | 
  | 
 
| Employee-related expense | 
  | 
  | 
1,149 | 
  | 
  | 
  | 
1,258 | 
  | 
 
| Warehousing, inventory-related and other | 
  | 
  | 
584 | 
  | 
  | 
  | 
756 | 
  | 
 
|   | 
  | 
$ | 
1,922 | 
  | 
  | 
$ | 
2,387 | 
  | 
 
|   Deferred revenue:   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
| Unshipped product and unredeemed product vouchers | 
  | 
$ | 
1,005 | 
  | 
  | 
$ | 
2,390 | 
  | 
 
| Auto ship advances | 
  | 
  | 
1,977 | 
  | 
  | 
  | 
1,985 | 
  | 
 
| Other | 
  | 
  | 
109 | 
  | 
  | 
  | 
131 | 
  | 
 
|   | 
  | 
$ | 
3,091 | 
  | 
  | 
$ | 
4,506 | 
  | 
 
 
     
   As of  December 31, 2020, cash and cash equivalents include $12.5 million held in banks located within China subject to foreign currency controls. 
     
  
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