Debt (Narrative) (Details)			1 Months Ended	3 Months Ended			4 Months Ended	12 Months Ended
	Jan. 30, 2018 USD ($) Installment	Dec. 31, 2017 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2003	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015	Dec. 31, 2014 USD ($)
Debt Instrument [Line Items]
Third party debt, non-current		$ 786,000		$ 0				$ 786,000	$ 0
Repayment of outstanding principal								$ 0	2,500,000
Street Capital Loan, Description								In 2014, following Street Capital’s distribution of its ownership interest in HGI to Street Capital stockholders as a dividend in kind, the unpaid balance of the Street Capital Loan began accruing interest at a rate per annum equal to the lesser of the Wall St. Journal (“WSJ”) prime rate + 2.0%, or the maximum rate allowable by law. As of December 31, 2015, the interest rate on the loan was 5.50%. In the third quarter of 2016, following an amendment to the loan agreement, the Street Capital Loan began accruing interest at a rate per annum equal to the WSJ prime rate + 1.0%. The Company also agreed to a monthly payment schedule to begin in the third quarter of 2016, and Street Capital removed the security from the Company’s assets. As of December 31, 2017, the interest rate on the loan was 5.50%.
Proceeds from debt payable to related party								$ 750,000	1,099,000
Accrued interest paid								3,000	187,000
Expense incurred based on profit share provision for principle and guarantee transaction								100,000	175,000
Revolving Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit		$ 750,000		0				750,000	0
Line of credit, interest								$ 4,000
Line of credit, outstanding amount period								1 month
Trust [Member]
Debt Instrument [Line Items]
Related party loan, Interest rate						10.00%
Proceeds from debt payable to related party						$ 400,000
Related party loan, maturity period						90 days
Accrued interest paid						$ 8,000
Affiliated Entity and Chief Executive Officer [Member]
Debt Instrument [Line Items]
Related party loan, Interest rate					10.00%
Proceeds from debt payable to related party					$ 700,000
Related party loan, maturity period					180 days
Accrued interest paid									19,000
Affiliated Entity [Member] | Revolving Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit aggregate borrowing capacity				1,500,000					1,500,000
Interest rate description								Aggregate loans under the Line of Credit up to $1.0 million incur interest at a variable rate per annum based on the rate charged to the Entity by its bank, plus 2.0%. Amounts outstanding at any time in excess of $1.0 million incur interest at a rate of 8.0% per annum.
Line of credit, annual commitment fee				$ 15,000
Line of credit, commitment fee payment description								monthly basis
Maturity description								The Line of Credit matures at the earlier of (i) three years from the date of the Agreement, (ii) the termination of the Entity’s line of credit with its bank, or (iii) forty-five (45) days following the date the Company closes a new credit facility with a financial institution. During 2017, the Company borrowed $750,000 on the Line of Credit and made one repayment of the full amount, including approximately $4,000 of interest. The total amount was outstanding for a one month period.
Expense incurred based on profit share provision for principle and guarantee transaction								$ 34,000
Heritage Global LLC [Member]
Debt Instrument [Line Items]
Interest rate on promissory note		6.50%						6.50%
Percentage of default interest amount		12.00%
Description of event of default								An “Event of Default” means: (a) any failure of HGLLC to pay when due any amount thereunder, when and as due, (b) any failure on the part of HGLLC to pay upon 54 Finance’s demand any fees, costs, expenses or other charges hereunder or otherwise due to HGLLC under the Note or the Guaranty, (c) any breach, failure or default under the Guaranty, (d) HGLLC or HGI repudiates or revokes, or purports to repudiate or revoke, any obligation under the Note or the Guaranty, or the obligation of HGI under the Guaranty is limited or terminated by operation of law or by HGI, or (e) HGLLC or HGI shall be or become insolvent, however defined, or admit in writing its inability to pay debts as they mature, or make a general assignment for the benefit of its creditors, or shall institute any bankruptcy, insolvency or similar proceeding under the laws of any jurisdiction, or shall take any action to authorize such proceeding.
Heritage Global LLC [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Litigation settlement, amount paid behalf of subsidiary	$ 1,260,000
Number of installments | Installment	36
Litigation settlement installments amount due	$ 35,000
Remaining outstanding debt balance payable date	Jan. 30, 2021
Street Capital Loan [Member]
Debt Instrument [Line Items]
Related party loan, Interest rate							10.00%	5.50%		5.50%
Wall St. Journal ("WSJ") prime rate [Member]
Debt Instrument [Line Items]
Interest rate per annum					1.00%						2.00%
Bank Plus 2.0% [Member] | Affiliated Entity [Member] | Revolving Line of Credit [Member]
Debt Instrument [Line Items]
Interest rate per annum				2.00%
Line of credit				$ 1,000,000					1,000,000
8.0% Interest Rate [Member] | Affiliated Entity [Member] | Revolving Line of Credit [Member]
Debt Instrument [Line Items]
Related party loan, Interest rate				8.00%
Line of credit				$ 1,000,000					$ 1,000,000
Other Third Party Debt [Member]
Debt Instrument [Line Items]
Third party debt, non-current			$ 2,500,000								$ 2,500,000
Debt Instrument, Interest Rate, Stated Percentage			6.00%			6.00%					6.00%
Debt Instrument, Maturity Date			Jan. 15, 2017			Jan. 15, 2015					Jan. 15, 2016
Repayment of outstanding principal					$ 2,500,000