SUBSEQUENT EVENTS - Merger with Digirad Corporation (Details)			2 Months Ended		9 Months Ended
	Apr. 03, 2019 USD ($)	Sep. 10, 2018 shares	Apr. 08, 2019 USD ($)	Feb. 23, 2019 USD ($)	Sep. 30, 2018 USD ($) shares	Sep. 30, 2017 USD ($)	Dec. 17, 2018 shares	Oct. 01, 2018 USD ($)	Jun. 01, 2018 shares	Dec. 31, 2017 shares
Subsequent Event [Line Items]
Common stock, shares outstanding (in shares)					2,396,219					2,396,219
Payment of overadvance | $					$ 23,989,000	$ 31,961,000
Jeffrey E. Eberwein
Subsequent Event [Line Items]
Common stock, shares outstanding (in shares)									415,012
Percentage of outstanding shares									17.00%
Jeffrey E. Eberwein | Subsequent Event
Subsequent Event [Line Items]
Percentage of outstanding shares							17.40%
ATRM Holdings, Inc. | Digirad Corporation
Subsequent Event [Line Items]
Consideration issue in business acquisition, number of shares issued per share of common stock owned		0.4
Digirad Corporation | Jeffrey E. Eberwein
Subsequent Event [Line Items]
Common stock, shares outstanding (in shares)		869,152
Percentage of outstanding shares		4.30%
ATRM Holdings, Inc. | Jeffrey E. Eberwein
Subsequent Event [Line Items]
Percentage of outstanding shares		17.40%
ATRM Holdings, Inc. | Common Class B | LSVI
Subsequent Event [Line Items]
Common stock, shares outstanding (in shares)		216,094
ATRM Holdings, Inc. | Common Class B | LSVI | Subsequent Event
Subsequent Event [Line Items]
Common stock, shares outstanding (in shares)							216,094
ATRM Holdings, Inc. | Series B Cumulative Preferred Stock | LSVI
Subsequent Event [Line Items]
Common stock, shares outstanding (in shares)									209,800
ATRM Holdings, Inc. | Series B Cumulative Preferred Stock | LSV Co-Invest I
Subsequent Event [Line Items]
Common stock, shares outstanding (in shares)		363,651							353,060
ATRM Holdings, Inc. | Series B Cumulative Preferred Stock | LSV Co-Invest I | Subsequent Event
Subsequent Event [Line Items]
Common stock, shares outstanding (in shares)							363,651
KBS Loan Agreement
Subsequent Event [Line Items]
Line of credit with maximum borrowing availability | $					$ 4,000,000
Eight Amendment To Loan And Security Agreement | KBS Loan Agreement | Subsequent Event
Subsequent Event [Line Items]
Line of credit with maximum borrowing availability | $								$ 600,000.0
Debt instrument periodic payment | $				$ 75,000
Payment of overadvance | $	$ 600,000.0
Promissory note payable to Gerber Finance | Subsequent Event
Subsequent Event [Line Items]
Debt instrument periodic payment | $			$ 75,000.0