Debt (Details) - USD ($) $ in Thousands			1 Months Ended														3 Months Ended		12 Months Ended
Debt (Details) - USD ($) $ in Thousands	Jul. 02, 2020	May 06, 2020	Nov. 30, 2021	Sep. 30, 2021	Aug. 31, 2021	Jul. 31, 2021	Jun. 30, 2021	Apr. 30, 2021	Sep. 30, 2020	Aug. 31, 2020	Mar. 31, 2020	Mar. 25, 2020	Jan. 31, 2020	Jan. 01, 2019	Aug. 31, 2018	May 31, 2017	Sep. 30, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2021	Jun. 19, 2020	Dec. 31, 2018	Dec. 31, 2017
Debt (Details) [Line Items]
Received advance amount											$ 150		$ 150					$ 120
Collection of invoice, description											On March 25, 2020, the related parties and others converted their advances into unsecured notes. The Company paid the advance fees of $8 in cash, and recorded them as interest expense in the quarter ended March 31, 2020.In August and September 2020, the Company received, from two related parties, advances aggregating $83 in cash against certain accounts receivable of the Company. Upon collection of an invoice, the Company agreed to repay the advance to the lenders on a pro rata basis together with a 5% advance fee. The Company has accrued the advance fees of $4 which is included in interest expense in the quarter ended September 30, 2020. During the three months from October to December 2020, the Company received from related parties and others advances aggregating $120 in cash against certain accounts receivable. The Company agreed to repay the advance to the lenders on a pro rata basis together with a 5% advance fee. The Company repaid $20 of the advances in December 2020. The Company has accrued the advance fees of $6 which is included in interest expense in the quarter ended December 31, 2020. In March 2021, the Company received, from related parties, advances aggregating $25 in cash against certain accounts receivable of the Company. Upon collection of an invoice, the Company agreed to repay the advance to the lenders on a pro rata basis together with a 5% advance fee.		On March 25, 2020, the related parties and others converted their advances into unsecured notes. The Company paid the advance fees of $8 in cash, and recorded them as interest expense in the quarter ended March 31, 2020.In August and September 2020, the Company received, from two related parties, advances aggregating $83 in cash against certain accounts receivable of the Company. Upon collection of an invoice, the Company agreed to repay the advance to the lenders on a pro rata basis together with a 5% advance fee. The Company has accrued the advance fees of $4 which is included in interest expense in the quarter ended September 30, 2020. During the three months from October to December 2020, the Company received from related parties and others advances aggregating $120 in cash against certain accounts receivable. The Company agreed to repay the advance to the lenders on a pro rata basis together with a 5% advance fee. The Company repaid $20 of the advances in December 2020. The Company has accrued the advance fees of $6 which is included in interest expense in the quarter ended December 31, 2020. In March 2021, the Company received, from related parties, advances aggregating $25 in cash against certain accounts receivable of the Company. Upon collection of an invoice, the Company agreed to repay the advance to the lenders on a pro rata basis together with a 5% advance fee.					The Company agreed to repay the advance to the lenders on a pro rata basis together with a 5% advance fee.
Payments for advance amount																		$ 20
Interest expense																		6
Accounts receivable advances in cash																					$ 25
Advance fee, percentage					5.00%			5.00%													5.00%
Advance fee																					$ 1
Accounts receivable advance								$ 49											$ 66
Accrued accounts receivable								$ 6											$ 3
Repaid accounts receivable, description								In addition the Company repaid to another affiliate $64 of Accounts Receivable Advances and $4 in accrued but unpaid 5% advance fees.
Received cash from affiliates				$ 36	$ 50	$ 10
Accounts receivable, description						The company accrued a 5% advance fee and recorded $1 as interest expense during the three months ended September 30, 2021. Upon collection of the accounts receivable the Company will repay the advance plus the 5% fee.
Interest expense																	$ 4
Advance fees																	5.00%
Unpaid advances																			5.00%
Value of warrants																				$ 160
Unsecured interest rate				20.00%													20.00%
Secured convertible notes, description															The unsecured notes are mandatorily convertible into Common Stock at a conversion rate of the lesser of $0.50 per share or the price per share of Common Stock upon closing a new financing of at least $1,000 in aggregate proceeds. The unsecured notes bear interest at the rate of 6% per annum. The secured notes are mandatorily convertible into Common Stock at a conversion rate of the lesser of $0.50 per share or the price per share of Common Stock, upon closing a new financing of at least $1,000 in aggregate proceeds. The secured notes bear interest at the rate of 10% per annum and are secured by an interest in all the Company’s rights, title and interest in, to and under its intellectual property. Should the secured notes remain outstanding following the maturity date an additional 30% of the note’s principal amount shall become due and payable. In December 2018, the Company increased the interest rate on its unsecured notes from 6% to 10% beginning January 1, 2019. In December of 2020, the note holders agreed to extend the due date of the notes from December 31, 2020 to December 31, 2021.In December 2017, the Company issued additional secured convertible promissory notes to investors and affiliates of the Company aggregating $150 in cash. The secured notes have substantially the same terms as the secured notes issued in the May 2017 financing. In August 2018, the Company issued secured convertible promissory notes to investors and affiliates of the Company aggregating $341, of which $205 was paid in cash, $75 was exchanged for the remaining advances described above and $61 was in the form of an Original Issue Discount (“OID”) on these amounts. The secured notes are mandatorily convertible into Common Stock at a conversion rate of the lesser of $0.50 per share or the price per shareof Common Stock upon closing a new financing of at least $1,000 in aggregate proceeds. The secured notes bear interest at the rate of 10% per annum and are secured by an interest in all the Company’s rights, title and interest in, to and under its intellectual property. Should the secured notes remain outstanding following the maturity date an additional 30% of the note’s principal amount shall become due and payable. In December of 2020, the note holders agreed to extend the due date of the notes from December 31, 2020 to December 31, 2021.
Notes payable, description												The unsecured notes are convertible by the holder into common stock at any time at a price per share of $0.50. Upon closing a new financing of at least $1,000 in aggregate proceeds, the Company can force conversion at a price equal to the lesser of $0.50 per share or the price per share of the new financing. The notes bear interest at the rate of 10%per annum and are due December 31, 2021.On May 6, 2020, the Company received loan proceeds in the amount of approximately $123 under the Paycheck Protection Program (“PPP”). The PPP, established as part of the Coronavirus Aid, Relief and Economic Security Act (“CARES Act”), provides for loans to qualifying businesses for amounts up to 2.5 times of the average monthly payroll expenses of the qualifying business. The Companies may apply for the loans and accrued interest to be forgiven after a period of either eight or twenty-four weeks, as long as the borrower uses the loan proceeds for eligible purposes, including payroll, benefits, rent and utilities, and maintains its payroll levels. The amount of loan forgiveness may be reduced if the borrower terminates employees or reduces salaries during the period in question. Under the terms of the related promissory note, the unforgiven portion of the PPP loan is payable over two years at an interest rate of 1%, with a deferral of payments for the first six months. The Company used the proceeds for purposes consistent with the PPP. While the Company currently believes that its use of the loan proceeds meet the conditions for forgiveness of the loan, we cannot assure you that we did not take actions that caused the Company to be ineligible for forgiveness of the loan, in whole or in part. On June 19, 2020, the Company issued an additional unsecured note for $250,000. The note has the same terms and maturity date as the Company’s other unsecured notes. On July 1, 2020 the Company entered into a settlement agreement with one of its vendors whereby the Company paid $135 in cash and issued a promissory note in the amount of $130 in settlement of approximately $537 in outstanding accounts payable. The note bears interest at the rate of 4% per annum and is due in installments of $40, $45 and $45 on or before the anniversary date of the note over the next three years. The settlement agreement discussed above resulted in gain of $272 recorded as other income in the statement of operations. On February 28, 2021, the Company issued an aggregate of $75 in unsecured notes, $30 to related parties and $45 to other investors. The Company received $15 in cash and $15 in exchange for an account receivable advance, received in the prior year, from related parties, and $45 in cash from other investors. The unsecured notes are convertible by the holder into common stock at any time at a price per share of $0.50. Upon closing a new financing of at least $1,000 in aggregate proceeds, the Company can force conversion at a price equal to the lesser of $0.50 per share or the price per share of the new financing.
Outstanding accounts payable																		$ 313		$ 313
First installment							$ 40
Accrued interest expense							$ 5												$ 305
Interest rate percentage							4.00%
Other income				$ 125	$ 125
Investments and cash				$ 75													$ 75
Accrued interest expense																			$ 349
Percentage of debt discount amortization																			0.00%
Related Party One [Member]
Debt (Details) [Line Items]
Received advance amount										$ 83
Collection of invoice, description										Upon collection of an invoice, the Company agreed to repay the advance to the lenders on a pro rata basis together with a 5% advance fee.
Related Party Two [Member]
Debt (Details) [Line Items]
Received advance amount									$ 83
Collection of invoice, description									Upon collection of an invoice, the Company agreed to repay the advance to the lenders on a pro rata basis together with a 5% advance fee.
Related Party [Member]
Debt (Details) [Line Items]
Unsecured interest rate			20.00%																20.00%
Accrued interest expense			$ 50																$ 126
Cash			$ 100																50
Related party cash																			50
Investor [Member]
Debt (Details) [Line Items]
Interest expense																			179
Unsecured Convertible Promissory Notes [Member]
Debt (Details) [Line Items]
Aggregating amount of debt															$ 346				760
Demand notes																			$ 200
Debt conversion, description															The short-term notes are mandatorily convertible into Common Stock at a conversion rate of the lesser of $0.50 per share or the price per share of Common Stock, upon closing a new debt and/or equity financing of at least $1,000 in aggregate proceeds.				The long-term notes are mandatorily convertible into Common Stock at a conversion rate of the lesser of $0.50 per share (initially, $1.30 per share and subsequently reduced in connection with the May 2017 described below) or the price per share of Common Stock, upon closing a new debt and or equity financing of at least $1,000 in aggregate proceeds.
Shares of common stock (in Shares)																			277
Value of warrants																			$ 204
Warrants (in Shares)																			277
Unsecured interest rate															10.00%
Secured Convertible Promissory Notes [Member]
Debt (Details) [Line Items]
Accounts receivable advances in cash															$ 75
Aggregating amount of debt															341	$ 325								$ 150
Debt conversion, description																In addition, certain investors and affiliates of the Company that had taken part in the November 2016 financing, and that also participated in the May 2017 financing, exchanged $450 of unsecured convertible promissory notes received in the November 2016 financing for $250 in secured notes with the same terms as the secured notes issued in the May 2017 financing and $200 in unsecured notes with the same terms as the November 2016 financing. The unsecured notes are mandatorily convertible into Common Stock at a conversion rate of the lesser of $0.50 per share or the price per share of Common Stock upon closing a new financing of at least $1,000 in aggregate proceeds.			The secured notes are mandatorily convertible into Common Stock at a conversion rate of the lesser of $0.50 per share or the price per share of Common Stock, upon closing a new financing of at least $1,000 in aggregate proceeds. The secured notes bear interest at the rate of 10% per annum and are secured by an interest in all the Company’s rights, title and interest in, to and under its intellectual property. Should the secured notes remain outstanding following the maturity date an additional 30% of the note’s principal amount shall become due and payable.
Unsecured interest rate																6.00%
Paid in cash															205
Debt Conversion, Original Debt, Amount															$ 61
Unsecured Debt [Member]
Debt (Details) [Line Items]
Aggregating amount of debt																						$ 250,000
Unsecured Debt [Member] \| Related Parties and Other Investors [Member]
Debt (Details) [Line Items]
Accounts receivable advances in cash												$ 75
Aggregating amount of debt												150
Paid in cash												$ 75
Paycheck Protection Program [Member]
Debt (Details) [Line Items]
Debt conversion, description		the Company received loan proceeds in the amount of approximately $123 under the Paycheck Protection Program (“PPP”). The PPP, established as part of the Coronavirus Aid, Relief and Economic Security Act (“CARES Act”), provides for loans to qualifying businesses for amounts up to 2.5 times of the average monthly payroll expenses of the qualifying business. The Companies may apply for the loans and accrued interest to be forgiven after a period of either eight or twenty-four weeks, as long as the borrower uses the loan proceeds for eligible purposes, including payroll, benefits, rent and utilities, and maintains its payroll levels. The amount of loan forgiveness may be reduced if the borrower terminates employees or reduces salaries during the period in question. Under the terms of the related promissory note, the unforgiven portion of the PPP loan is payable over two years at an interest rate of 1%, with a deferral of payments for the first six months.
Promissory Note [Member]
Debt (Details) [Line Items]
Unsecured interest rate	4.00%
Promissory Note [Member] \| Settlement Agreement [Member]
Debt (Details) [Line Items]
Aggregating amount of debt	$ 130
Paid in cash	135
Outstanding accounts payable	537
Other income	$ 272
Minimum [Member] \| Unsecured Convertible Promissory Notes [Member]
Debt (Details) [Line Items]
Interest rate																							6.00%
Unsecured interest rate														6.00%
Maximum [Member] \| Unsecured Convertible Promissory Notes [Member]
Debt (Details) [Line Items]
Interest rate																							10.00%
Unsecured interest rate														10.00%

iSign Solutions Inc. 10-K