Merger - Narrative (Details)			3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 10, 2019 USD ($) $ / shares shares	Sep. 09, 2019	Sep. 30, 2020 USD ($) $ / shares	Sep. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Sep. 30, 2020 USD ($) $ / shares	Sep. 30, 2019 USD ($)	Sep. 17, 2020 $ / shares	Dec. 31, 2019 USD ($)
Business Acquisition [Line Items]
Series A Cumulative Perpetual Preferred Stock, dividend rate	0.100					0.100
Series A Cumulative Perpetual Preferred Stock, par value (USD per share)	$ 0.0001
Preferred stock, dividend rate percentage						10.00%
Preferred stock, par value (in usd per share) | $ / shares			$ 0.0001			$ 0.0001
Goodwill			$ 9,978,000			$ 9,978,000			$ 9,978,000
Acquisition related costs			$ 0	$ 1,058,000		$ 0	$ 2,058,000
ATRM Holdings, Inc.
Business Acquisition [Line Items]
Shares issued in business acquisition (In shares) | shares	1,615,637
Acquisition date consideration fair value	$ 17,452,000
Share price (in dollars per share) | $ / shares	$ 10.00
Goodwill	$ 8,233,000
Intangibles assets acquired	$ 19,470,000
Acquisition related costs					$ (2,300,000)
Series A Preferred Stock
Business Acquisition [Line Items]
Digirad shares issued per ATRM share (in shares)		0.03
Preferred stock, par value (in usd per share) | $ / shares								$ 0.0001
Series A Preferred Stock | ATRM Holdings, Inc.
Business Acquisition [Line Items]
Digirad shares issued per ATRM share (in shares)	0.03
Shares issued in business acquisition (In shares) | shares	1,615,637
Series B Preferred Stock | ATRM Holdings, Inc.
Business Acquisition [Line Items]
Digirad shares issued per ATRM share (in shares)	2.5	2.5
ATRM Holdings, Inc.
Business Acquisition [Line Items]
Preferred stock, dividend rate percentage	10.00%
Preferred stock, par value (in usd per share) | $ / shares	$ 0.001