ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Investments (Details) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($) investment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of long-term investments \| investment	2
Payment, long-term investment \| $	$ 0	$ 3,000	$ 0

The cash outflow for the purchase of loan receivable arising from the financing of goods and services.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3213-108585

Name:	us-gaap_PaymentsToAcquireLoansReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration