Related Party Transactions (Details)												3 Months Ended	9 Months Ended
	Jul. 10, 2020 shares	Sep. 10, 2019 USD ($) $ / shares	Sep. 09, 2019 USD ($) $ / shares shares	Sep. 06, 2019	Jul. 30, 2019 USD ($)	May 01, 2019 USD ($)	Apr. 03, 2019 USD ($)	Apr. 01, 2019 USD ($)	Mar. 27, 2019 USD ($)	Dec. 14, 2018 USD ($)	Jul. 27, 2015 USD ($) shares	Sep. 30, 2019 shares	Sep. 30, 2020 USD ($) $ / shares shares	Sep. 17, 2020 $ / shares shares	Mar. 05, 2020 USD ($)	Jan. 30, 2020 USD ($)	Dec. 31, 2019 shares	Mar. 29, 2019 USD ($)	Dec. 17, 2018 USD ($)
Related Party Transaction [Line Items]
Amount													$ 2,356,000
Shares owned (in shares) | shares													4,750,951				2,050,659
Preferred stock, dividend rate percentage													10.00%
Preferred stock, outstanding (in shares) | shares													1,915,637
Issuance of preferred stock (in shares) | shares												1,916,000
Gross proceeds from private placement			$ 3,000,000.0
Shares reserved for future issuance (in shares) | shares														1,492,321
Preferred stock, par value (in usd per share) | $ / shares													$ 0.0001
Perma-Fix
Related Party Transaction [Line Items]
Investment made as part of Subscription Agreement											$ 1,000,000.0
Shares acquired (in shares) | shares											71,429
Investment owned, at fair value													$ 70,000
Board of Directors Chairman
Related Party Transaction [Line Items]
Obligations under the Limited Guaranty															$ 500,000	$ 2,500,000		$ 1,500,000
Board of Directors Chairman | Preferred Stock [Member]
Related Party Transaction [Line Items]
Issuance of preferred stock (in shares) | shares	114,624
Board of Directors Chairman | Put Option
Related Party Transaction [Line Items]
Price of stock sold (in dollars per share) | $ / shares													$ 10.00
Indexed shares (in shares) | shares													100,000
Option indexed, fair value													$ 1,000,000.0
Board of Directors Chairman | Affiliated Entity
Related Party Transaction [Line Items]
Amount													$ 300,000
Star Procurement, LLC
Related Party Transaction [Line Items]
Joint venture interest										50.00%
Capital contribution										$ 1,000,000.0
Digirad Corp | Board of Directors Chairman
Related Party Transaction [Line Items]
Percentage of outstanding shares			4.30%										7.40%
Preferred stock, outstanding (in shares) | shares													1,310,036
ATRM Holdings, Inc. | Board of Directors Chairman
Related Party Transaction [Line Items]
Percentage of outstanding shares			17.40%
ATRM Holdings, Inc.
Related Party Transaction [Line Items]
Preferred stock, dividend rate percentage		10.00%
Preferred stock, par value (in usd per share) | $ / shares		$ 0.001
Lone Star Value Investors, LP | ATRM Holdings, Inc. | Call Option
Related Party Transaction [Line Items]
Shares owned (in shares) | shares													216,174
LSVM
Related Party Transaction [Line Items]
Issuance of preferred stock (in shares) | shares	300,000
Purchase price								$ 100.00
Series B Preferred Stock | ATRM Holdings, Inc.
Related Party Transaction [Line Items]
Preferred stock, dividend rate percentage			10.00%
Series B Preferred Stock | Lone Star Value Investors, LP | ATRM Holdings, Inc.
Related Party Transaction [Line Items]
Shares owned (in shares) | shares			222,577
Series B Preferred Stock | Lone Star Value Co-Invest I, LP | ATRM Holdings, Inc.
Related Party Transaction [Line Items]
Shares owned (in shares) | shares			374,562
ATRM Holdings, Inc. | Affiliated Entity
Related Party Transaction [Line Items]
Aggregate maximum amount to ATRM					$ 800,000	$ 400,000
Subsequent incremental payments to ATRM						$ 10,000.00
Eberwein Trust | Board of Directors Chairman | Preferred Stock [Member]
Related Party Transaction [Line Items]
Issuance of preferred stock (in shares) | shares	113,780
LSV GP | Board of Directors Chairman | Preferred Stock [Member]
Related Party Transaction [Line Items]
Issuance of preferred stock (in shares) | shares	844
Waterford Lease
Related Party Transaction [Line Items]
Purchase price							$ 1,000,000.0
Lease period							120 months
Waterford Lease | Minimum
Related Party Transaction [Line Items]
Base rent payments							$ 1,200,000
Waterford Lease | Maximum
Related Party Transaction [Line Items]
Base rent payments							1,300,000
Park Lease
Related Party Transaction [Line Items]
Purchase price							$ 2,900,000
Lease period							120 months
Park Lease | Minimum
Related Party Transaction [Line Items]
Base rent payments							$ 3,300,000
Park Lease | Maximum
Related Party Transaction [Line Items]
Base rent payments							$ 3,600,000
Oxford Lease
Related Party Transaction [Line Items]
Purchase price									$ 1,200,000
Lease period									120 months
Oxford Lease | Minimum
Related Party Transaction [Line Items]
Base rent payments									$ 1,400,000
Oxford Lease | Maximum
Related Party Transaction [Line Items]
Base rent payments									$ 1,500,000
North Country Steel Inc.
Related Party Transaction [Line Items]
Lease period				5 years
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Due January 12, 2020
Related Party Transaction [Line Items]
Promissory note													$ 700,000
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Due January 12, 2020 | Minimum
Related Party Transaction [Line Items]
Interest rate													10.00%
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Due January 12, 2020 | Maximum
Related Party Transaction [Line Items]
Interest rate													12.00%
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Due June 1, 2020
Related Party Transaction [Line Items]
Promissory note													$ 1,200,000
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Due June 1, 2020 | Minimum
Related Party Transaction [Line Items]
Interest rate													10.00%
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Due June 1, 2020 | Maximum
Related Party Transaction [Line Items]
Interest rate													12.00%
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Due November 30, 2020
Related Party Transaction [Line Items]
Promissory note													$ 300,000
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Due November 30, 2020 | Minimum
Related Party Transaction [Line Items]
Interest rate													10.00%
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Due November 30, 2020 | Maximum
Related Party Transaction [Line Items]
Interest rate													12.00%
Notes Payable, Other Payables | Lone Star Value Management, Unsecured Promissory Note, Issued December 17, 2018
Related Party Transaction [Line Items]
Promissory note																			$ 300,000
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Issued December 14, 2018
Related Party Transaction [Line Items]
Promissory note										$ 300,000
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Issued December 14, 2018 | Minimum
Related Party Transaction [Line Items]
Interest rate										10.00%
Notes Payable, Other Payables | ATRM Unsecured Promissory Note, Issued December 14, 2018 | Maximum
Related Party Transaction [Line Items]
Interest rate										12.00%
Private Placement
Related Party Transaction [Line Items]
Issuance of preferred stock (in shares) | shares			300,000
Price of stock sold (in dollars per share) | $ / shares		$ 10.00	$ 10.00
Gross proceeds from private placement		$ 3,000,000.0
Series A Preferred Stock
Related Party Transaction [Line Items]
Digirad shares issued per ATRM share (in shares)			0.03
Shares reserved for future issuance (in shares) | shares														1,492,321
Preferred stock, par value (in usd per share) | $ / shares														$ 0.0001
ATRM Holdings, Inc. | Series A Preferred Stock
Related Party Transaction [Line Items]
Digirad shares issued per ATRM share (in shares)		0.03
ATRM Holdings, Inc. | Series B Preferred Stock
Related Party Transaction [Line Items]
Digirad shares issued per ATRM share (in shares)		2.5	2.5