ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($) region	Jun. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of regions in which company sells products | region	3
Credit card receivables	$ 1,700		$ 1,600
Cash and cash equivalents held in foreign bank accounts	22,900		19,900
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Line Items]
Restricted cash	6,500		8,700
Accounts receivable, net of allowance	176		106
Allowance for doubtful accounts	600		800
Other assets	10,433		3,894
Deposits for building leases	2,200		2,000
Fair trade commission deposits	1,500		1,700
Indefinite lived intangible assets	200		200
Notes payable	1,200		1,600
Notes payable, current portion	715		702
Other long-term liabilities	6,644		2,302
Uncertain income tax position	200		200
Accrued lease restoration costs	400		400
Defined benefit plan obligation		$ 300	400
Deferred commissions	2,356		2,449
Amortization of deferred commissions	1,200
Deferred revenue	5,702		5,274
Deferred revenue, revenue recognized during the period	3,200
Loyalty deferred revenue, ending balance	$ 3,579
Percentage of sale returns	1.50%
South Korea
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Line Items]
Net assets	$ 18,100		$ 14,400
Software Tools
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	3 months
Associate Fees
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	12 months