ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($) performance_obligation region	Dec. 31, 2017 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of regions in which company sells products | region	3
Credit card receivables	$ 2,800	$ 2,000
Cash and cash equivalents held in foreign bank accounts	20,900	30,600
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Line Items]
Restricted cash	8,800	9,100
Accounts receivable, net of allowance	124	273
Allowance for doubtful accounts	700	600
Other assets	3,828	3,876
Deposits for building leases	1,900	1,900
Fair trade commission deposits	1,700	1,700
Indefinite lived intangible assets	200	200
Notes payable	1,800	800
Notes payable, current portion	802	815
Other long-term liabilities	2,796	1,265
Uncertain income tax position	200	200
Accrued lease restoration costs	300	400
Defined benefit plan obligation	400	400
Lease incentive payable, noncurrent	1,400
Deferred commissions	3,124	3,880
Amortization of deferred commissions	2,200
Deferred revenue	6,960	8,561
Deferred revenue, revenue recognized during the period	5,700
Loyalty deferred revenue, ending balance	$ 4,677
Percentage of sale returns	1.50%
Revenue, number of performance obligations, product sales | performance_obligation	2
Revenue, performance obligations, term of services, online business tools	3 months
Revenue, number of performance obligations, online business tools | performance_obligation	3
South Korea
ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Line Items]
Net assets	$ 13,000	$ 32,700
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