Basis of Presentation - Narrative (Details)					3 Months Ended
	Sep. 10, 2019 USD ($) $ / shares shares	Sep. 09, 2019	Jun. 04, 2019	May 01, 2019	Mar. 31, 2020 USD ($) $ / shares shares	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) shares	May 31, 2019 shares
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Common stock shares authorized after reversed stock split (in shares) | shares					30,000,000		30,000,000	30,000,000
Reverse stock split			0.1
Series A Cumulative Perpetual Preferred Stock, dividend rate	0.100				0.10
Series A Cumulative Perpetual Preferred Stock, par value (USD per share)	$ 0.0001
Preferred stock, liquidation preference per share (USD per share) | $ / shares					$ 10.00
Capitalized implementation costs					$ 500,000
(Loss) income from operations by segment					(2,604,000)	$ (1,135,000)
Accumulated deficit					(121,482,000)	(118,500,000)	$ (118,529,000)
Net cash provided by (used in) operating activities					623,000	$ (2,185,000)
Short-term debt and current portion of long-term debt					1,211,000		4,036,000
Payable to related parties					2,034,000		1,920,000
Derivative liability							$ 10,000
ATRM Holdings, Inc.
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Shares issued in business acquisition (In shares) | shares	1,615,637
Series A Preferred Stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Digirad shares issued per ATRM share (in shares)		0.03
Series A Preferred Stock | Put Option
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Derivative liability					$ 1,000,000.0
Series A Preferred Stock | ATRM Holdings, Inc.
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Digirad shares issued per ATRM share (in shares)	0.03
Shares issued in business acquisition (In shares) | shares	1,615,637				1,615,637
Series B Preferred Stock | ATRM Holdings, Inc.
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Digirad shares issued per ATRM share (in shares)	2.5	2.5
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reverse stock split				0.2
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reverse stock split				0.1
ATRM Holdings, Inc.
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Preferred stock, dividend rate percentage	10.00%
Preferred stock, par value (in usd per share) | $ / shares	$ 0.001