SUBSEQUENT EVENTS - Promissory Note Sale to Digirad (Details) - Promissory Note - Digirad Unsecured Promissory Note, Issued December 12, 2018 - Subsequent Event $ in Millions	Dec. 14, 2018 USD ($)
Subsequent Event [Line Items]
Debt principal amount	$ 0.3
Minimum
Subsequent Event [Line Items]
Debt interest rate	10.00%
Maximum
Subsequent Event [Line Items]
Debt interest rate	12.00%

Face (par) amount of debt instrument at time of issuance.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant