Navidea Biopharmaceuticals (NAVB) 10-K 26 Mar 21 2020 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 15, 2021	Jun. 30, 2020
Document Information [Line Items]
Entity Registrant Name	NAVIDEA BIOPHARMACEUTICALS, INC.
Entity Central Index Key	0000810509
Trading Symbol	navb
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding (in shares)		28,567,298
Entity Public Float			$ 66,317,942
Entity Shell Company	false
Document Type	10-K
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Title of 12(b) Security	Common Stock, par value $.001 per share

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 2,670,495	$ 1,047,159
Stock subscriptions and other receivables	2,987,319	901,339
Inventory	169,798
Prepaid expenses and other	700,716	967,285
Total current assets	6,528,328	2,915,783
Property and equipment	845,379	1,207,537
Less accumulated depreciation and amortization	713,217	1,177,327
Property and equipment, net	132,162	30,210
Right-of-use lease assets	458,280	404,594
Less accumulated amortization	208,185	122,906
Right-of-use lease assets, net	250,095	281,688
License agreements, patents and trademarks	747,863	478,672
Less accumulated amortization	127,622	93,259
License agreements, patents and trademarks, net	620,241	385,413
Other assets	227,192	537,812
Total assets	7,758,018	4,150,906
Current liabilities:
Accounts payable	1,161,717	1,112,069
Accrued liabilities and other	2,512,994	2,150,974
Notes payable	745,443	305,955
Lease liabilities, current	294,951	250,553
Total current liabilities	4,715,105	3,819,551
Lease liabilities	296,006	512,344
Deferred revenue	700,000	700,000
Total liabilities	5,711,111	5,031,895
Commitments and contingencies (Note 13)
Stockholders’ equity (deficit):
Preferred stock; $.001 par value; 5,000,000 shares authorized; no shares issued or outstanding as of December 31, 2020 and 2019, respectively
Series D preferred stock subscribed; $.001 par value, 103,000 and 0 shares subscribed as of December 31, 2020 and 2019, respectively	132
Series D preferred stock subscriptions receivable	(10,300,000)
Common stock; $.001 par value; 300,000,000 shares authorized; 27,149,691 and 19,234,960 shares issued and outstanding as of December 31, 2020 and 2019, respectively	218,146	210,232
Common stock subscribed; $.001 par value, 995,000 and 902,162 shares subscribed as of December 31, 2020 and 2019, respectively	995	902
Common stock subscriptions receivable	(4,975,000)
Additional paid-in capital	375,428,014	345,847,676
Accumulated deficit	(359,056,683)	(347,671,102)
Total Navidea stockholders' equity (deficit)	1,315,604	(1,612,292)
Noncontrolling interest	731,303	731,303
Total stockholders’ equity (deficit)	2,046,907	(880,989)
Total liabilities and stockholders’ equity (deficit)	$ 7,758,018	$ 4,150,906

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Preferred stock subscriptions, subscribed (in shares)	103,000	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	27,149,691	19,234,960
Common stock, shares outstanding (in shares)	27,149,691	19,234,960
Common stock subscription, shares authorized (in shares)	995,000	902,162

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($)		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Revenue:
Revenue from contract with customer		$ 119,000	$ 38,000
Grant and other revenue		796,288	631,208
Total revenue		915,013	657,826
Cost of revenue		1,048	6,667
Gross profit		913,965	651,159
Operating expenses:
Research and development		4,930,187	5,338,267
Selling, general and administrative		6,694,959	6,275,409
Total operating expenses		11,625,146	11,613,676
Loss from operations	[1]	(10,711,181)	(10,962,517)
Other income (expense):
Interest income, net		11,344	25,288
Other expense, net		(21,854)	(7,613)
Total other (expense) income, net	[2]	(10,510)	17,675
Loss before income taxes		(10,721,691)	(10,944,842)
Provision for income taxes			(707)
Loss from continuing operations		(10,721,691)	(10,945,549)
Loss from discontinued operations, net of tax effect			(2,665)
Net loss		(10,721,691)	(10,948,214)
Income attributable to noncontrolling interest			(17)
Deemed dividend on Series C and Series D Preferred Stock beneficial conversion feature		(663,889)
Net loss attributable to common stockholders		$ (11,385,580)	$ (10,948,197)
Loss per common share (basic and diluted):
Continuing operations (in dollars per share)		$ (0.48)	$ (0.76)
Attributable to common stockholders (in dollars per share)		$ (0.48)	$ (0.76)
Weighted average shares outstanding (basic and diluted) (in shares)		23,896,001	14,393,360
Royalty [Member]
Revenue:
Revenue from contract with customer		$ 7,995	$ 16,665
License [Member]
Revenue:
Revenue from contract with customer		$ 110,730	$ 9,953
[1]	Loss from operations does not reflect the allocation of certain selling, general and administrative expenses, excluding depreciation and amortization, to our individual reportable segments, other than those expenses directly incurred by Navidea Europe, Navidea UK and MT.
[2]	Amounts consist primarily of interest income and interest expense, which are not currently allocated to our individual reportable segments.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Net loss	$ (10,721,691)	$ (10,948,214)
Unrealized gain on available-for-sale securities		730
Comprehensive loss	$ (10,721,691)	$ (10,947,484)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Deficit) - USD ($)	Preferred Stock [Member]Private Placement [Member]	Preferred Stock [Member]Series C Preferred Stock [Member]	Preferred Stock [Member]Series D Preferred Stock [Member]	Preferred Stock [Member]	Preferred Stock Subscription [Member]Private Placement [Member]	Preferred Stock Subscription [Member]Series C Preferred Stock [Member]	Preferred Stock Subscription [Member]Series D Preferred Stock [Member]	Preferred Stock Subscription [Member]	Preferred Stock Subscriptions Receivable [Member]Private Placement [Member]	Preferred Stock Subscriptions Receivable [Member]Series C Preferred Stock [Member]	Preferred Stock Subscriptions Receivable [Member]Series D Preferred Stock [Member]	Preferred Stock Subscriptions Receivable [Member]	Common Stock [Member]Private Placement [Member]	Common Stock [Member]Series C Preferred Stock [Member]	Common Stock [Member]Series D Preferred Stock [Member]	Common Stock [Member]	Common Stock Subscription [Member]Private Placement [Member]	Common Stock Subscription [Member]Series C Preferred Stock [Member]	Common Stock Subscription [Member]Series D Preferred Stock [Member]	Common Stock Subscription [Member]	Common Stock Subscriptions Receivable [Member]Private Placement [Member]	Common Stock Subscriptions Receivable [Member]Series C Preferred Stock [Member]	Common Stock Subscriptions Receivable [Member]Series D Preferred Stock [Member]	Common Stock Subscriptions Receivable [Member]	Additional Paid-in Capital [Member]Private Placement [Member]	Additional Paid-in Capital [Member]Series C Preferred Stock [Member]	Additional Paid-in Capital [Member]Series D Preferred Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]Private Placement [Member]	Retained Earnings [Member]Series C Preferred Stock [Member]	Retained Earnings [Member]Series D Preferred Stock [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]Private Placement [Member]	Noncontrolling Interest [Member]Series C Preferred Stock [Member]	Noncontrolling Interest [Member]Series D Preferred Stock [Member]	Noncontrolling Interest [Member]	AOCI Attributable to Parent [Member]	Private Placement [Member]	Series C Preferred Stock [Member]	Series D Preferred Stock [Member]	Total
Balance (in shares) at Dec. 31, 2018																10,019,535
Balance at Dec. 31, 2018																$ 200,391												$ 338,265,383				$ (336,722,905)				$ 668,321	$ (730)				$ 2,410,460
Issued restricted stock (in shares)																15,000
Issued restricted stock																$ 300																									300
Issued stock (in shares)													1,173,411			8,000,000
Issued stock													$ 1,513			$ 8,000									$ 1,088,487			5,158,441										$ 1,090,000			5,166,441
Adjustments related to reverse stock split (in shares)																(1,114)
Adjustments related to reverse stock split																												(3,385)													$ (3,385)
Issued stock to 401(k) plan (in shares)																8,128																									8,128
Issued stock to 401(k) plan																$ 8												19,580													$ 19,588
Value of warrants issued in connection with public offering																												261,288													261,288
Issued stock in payment of services (in shares)																20,000
Issued stock in payment of services																$ 20												14,780													14,800
Stock subscribed in connection with private placement (in shares)																				902,162
Stock subscribed in connection with private placement																				$ 902								811,044													811,946
Change in estimated fair value of MT warrants																																				63,000					63,000
Stock compensation expense																												232,058													232,058
Net loss																																(10,948,197)				(17)					(10,948,214)
Unrealized gain on available-for-sale securities																																					$ 730				730
Total comprehensive loss																																									$ (10,947,484)
Issued stock in payment of employee bonuses (in shares)																																									8,128
Issued stock																																									$ (841,559)
Issued restricted stock																$ 300																									300
Balance (in shares) at Dec. 31, 2019																19,234,960				902,162
Balance at Dec. 31, 2019																$ 210,232				$ 902								345,847,676				(347,671,102)				731,303					(880,989)
Issued restricted stock																$ 60																									60
Issued stock (in shares)		420,000	17,750										3,280,691			1,647,059	(902,162)
Issued stock		$ 420	$ 18										$ 3,281			$ 1,647	$ (902)									$ 4,162,758	$ 132,089	1,248,353										2,059	$ 4,163,178	$ 132,107	$ 1,250,000
Issued stock to 401(k) plan (in shares)																32,651																									32,651
Issued stock to 401(k) plan																$ 33												39,801													$ 39,834
Issued stock in payment of services (in shares)																23,810
Issued stock in payment of services																$ 24												70,177													70,201
Stock subscribed in connection with private placement (in shares)							132,250										995,000
Stock subscribed in connection with private placement							$ 132				(10,300,000)						$ 995				$ (4,975,000)				7,014,126		14,849,851											$ 2,040,121		4,549,983
Stock compensation expense																												230,522													230,522
Net loss																																(10,721,691)									(10,721,691)
Unrealized gain on available-for-sale securities
Total comprehensive loss																																									$ (10,721,691)
Issued stock in payment of employee bonuses (in shares)																94,159																									32,651
Issued stock in payment of employee bonuses																$ 94												171,428													$ 171,522
Issued stock																									$ (320)
Issued restricted stock (in shares)																60,000
Issued restricted stock																$ 60																									60
Issued stock upon exercise of warrants (in shares)																300,595
Issued stock upon exercise of warrants																$ 300												(300)
Deemed dividend																										466,667	197,223			(466,667)	(197,223)
Issued stock upon conversion (in shares)		(420,000)	(17,750)											1,425,076	827,280
Issued stock upon conversion		$ (420)	$ (18)											$ 1,425	$ 827											(1,005)	$ (809)
Issued stock in payment of Series C Preferred Stock fees (in shares)														14,205		209,205
Issued stock in payment of Series C Preferred Stock fees														$ 14												$ (14)
Issued stock pursuant to Jubilant MOU																$ 209												999,791													1,000,000
Balance (in shares) at Dec. 31, 2020								132,250								27,149,691				995,000
Balance at Dec. 31, 2020								$ 132				$ (10,300,000)				$ 218,146				$ 995				$ (4,975,000)				$ 375,428,014				$ (359,056,683)				$ 731,303					$ 2,046,907

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Deficit) (Parentheticals)	12 Months Ended
	Dec. 31, 2019USD ($)
Stock issuance cost	$ 841,559

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net loss	$ (10,721,691)	$ (10,948,214)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization of property and equipment	33,929	103,165
Amortization of license agreements, patents and trademarks	36,464	41,347
Non-cash lease expense	120,186
Loss on disposal and abandonment of patents and equipment	5,654	60,104
Stock compensation expense	230,521	232,058
Value of stock issued in payment of employee bonuses	171,522
Value of stock issued in payment for services	70,201	14,800
Value of stock issued to 401(k) plan for employer matching contributions	39,834	19,588
Changes in operating assets and liabilities:
Stock subscriptions and other receivables	839,020	(68,242)
Inventory	(169,798)
Prepaid expenses and other assets	1,019,230	696,718
Accounts payable	49,648	687,351
Accrued and other liabilities	348,410	(195,989)
Lease liabilities	(260,532)
Deferred revenue	13,609	2,584
Net cash used in operating activities	(8,173,793)	(9,354,730)
Cash flows from investing activities:
Proceeds from sales of available-for-sale securities		400,000
Maturities of available-for-sale securities		400,000
(Payments for purchases) proceeds from disposal of equipment	(135,881)	27,125
Proceeds from sales of equipment	1,042
Patent and trademark costs	(277,989)	(56,700)
Net cash (used in) provided by investing activities	(412,828)	770,425
Cash flows from financing activities:
Proceeds from issuance of preferred stock	5,975,000
Proceeds from issuance of common stock	4,442,560	7,086,915
Proceeds from note payable	366,000
Principal payments on notes payable	(368,553)	(359,061)
Net cash provided by financing activities	10,209,957	6,155,583
Net increase (decrease) in cash and cash equivalents	1,623,336	(2,428,722)
Cash and cash equivalents, beginning of period	1,047,159	3,475,881
Cash and cash equivalents, end of period	2,670,495	1,047,159
Preferred Stock Issuance Costs [Member]
Cash flows from financing activities:
Payment of stock issuance costs	(55,050)
Common Stock Issuance Costs [Member]
Cash flows from financing activities:
Payment of stock issuance costs	$ (150,000)	$ (572,271)

Note 1 - Organization and Summa

Note 1 - Organization and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Significant Accounting Policies [Text Block]	1. Organization and Summary of Significant Accounting Policies a. Organization and Nature of Operations: Navidea's Manocept platform is predicated on the ability to specifically target the CD206 Tc99m first Tc99m none In July 2011, Tc99m 100% In January 2015, 99.9% In June 2020, 100% On April 26, 2019, one twenty $.001 twenty one 201.0 10.1 not 300.0 $0.001 January 1, 2019. not b. Principles of Consolidation: c. Use of Estimates: d. Financial Instruments and Fair Value: ( 1 Cash and cash equivalents, stock subscriptions and other receivables, and accounts payable: ( 2 Notes payable: December 31, 2020 2019 December 31, 2020 2019, $745,000 $306,000, 11. ( 3 Warrants: June 2019, 600,000 7.5% $261,000 88.6%, 1.8% $0. 14 e. Stock-Based Compensation: December 31, 2020, two 2002 “2002 2014 “2014 2014 may may 2014 1,750,000 2002 no may Stock options granted under the 2002 2014 one four not ten 90 Stock-based payments to employees and directors, including grants of stock options and restricted stock, are recognized in the statements of operations based on their estimated fair values on the date of grant, subject to an estimated forfeiture rate. The fair value of each option award with time-based vesting provisions is estimated on the date of grant using the Black-Scholes option pricing model. The determination of fair value using the Black-Scholes option pricing model is affected by our stock price as well as assumptions regarding a number of complex and subjective variables, including expected stock price volatility, risk-free interest rate, expected dividends and projected employee stock option behaviors. The fair value of each option award with market-based vesting provisions is estimated on the date of grant using a Monte Carlo simulation. The determination of fair value using a Monte Carlo simulation is affected by our stock price as well as assumptions regarding a number of complex and subjective variables, including expected stock price volatility, risk-free interest rate, expected dividends and projected employee stock option behaviors. Expected volatilities are based on the Company's historical volatility, which management believes represents the most accurate basis for estimating expected future volatility under the current circumstances. Navidea uses historical data to estimate forfeiture rates. The expected term of stock options granted is based on the vesting period and the contractual life of the options. The risk-free rate is based on the U.S. Treasury yield in effect at the time of the grant. The assumptions used to calculate the fair value of stock option awards granted during the years ended December 31, 2020 2019 2020 2019 Expected volatility 86% - 102% 76% - 93% Weighted-average volatility 92% 86% Expected forfeiture rate 7.0% - 10.5% 15.1% - 15.5% Expected term (in years) 5.5 - 6.0 3.5 - 6.0 Risk-free rate 0.4% - 1.5% 2.4% - 2.5% Expected dividends — — The portion of the fair value of stock-based awards that is ultimately expected to vest is recognized as compensation expense over either ( 1 2 may not not 4. f. Cash and Cash Equivalents: three g. Stock Subscriptions and Other Receivables: 6. h. Inventory: first first 7. i. Property and Equipment: 8. j. Intangible Assets: 5 15 no 2020 2019, $278,000 $57,000, 2020 2019, $9,000 $58,000, k. Impairment or Disposal of Long-Lived Assets: may not No December 31, 2020 2019. l. Leases: 2018. 12 not 12. m. Revenue Recognition: We also earn revenues related to our licensing and distribution agreements. The consideration we are eligible to receive under our licensing and distribution agreements typically includes upfront payments, reimbursement for research and development costs, milestone payments, and royalties. Each licensing and distribution agreement is unique and requires separate assessment in accordance with current accounting standards. See Note 3. n. Research and Development Costs: o. Income Taxes: December 31, 2020 2019. Current accounting standards include guidance on the accounting for uncertainty in income taxes recognized in the financial statements. Such standards also prescribe a recognition threshold and measurement model for the financial statement recognition of a tax position taken, or expected to be taken, and provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition. The Company believes that the ultimate deductibility of all tax positions is highly certain, although there is uncertainty about the timing of such deductibility. As a result, no December 31, 2020 2019 not twelve December 31, 2020, 2017 2020 15. p. Series C and Series D Convertible Preferred Stock: 480, Distinguishing Liabilities from Equity 815, Derivatives and Hedging 470, Debt 268, Presentation in Financial Statements of Redeemable Preferred Stocks not not not 14. q. Recently Adopted Accounting Standards: February 2016, No. 2016 02, Leases (Topic 842 2016 02 842 In July 2018, No. 2018 10, Codification Improvements to Topic 842, No. 2018 11, Targeted Improvements to Topic 842, 2018 10 842 2016 02, Leases (Topic 842 2018 11 840, Leases 840 840. 2018 10 2018 11 2016 02 December 15, 2018. The Company adopted ASU 2016 02, 2018 10 2018 11 January 1, 2019 not 12 The adoption of ASU 2016 02 $407,000 January 1, 2019 2016 02 not 12. In June 2018, No. 2018 07, Compensation Stock Compensation (Topic 718 2018 07 718 718 2018 07 718 718 not 1 2 606, Revenue from Contracts with Customers 2018 07 December 15, 2018, 2018 07 not In July 2018, No. 2018 09, Codification Improvements 2018 09 2018 09 December 15, 2018 2018 09 not In August 2018, No. 2018 13, Fair Value Measurement (Topic 820 Disclosure Framework Changes to the Disclosure Requirements for Fair Value Measurement 2018 13 820. 2018 13 December 15, 2019. 2018 13 not r. Recently Issued Accounting Standards: December 2019, No. 2019 12, Income Taxes (Topic 740 2019 12 2019 12 740 2019 12 December 12, 2020, not 2019 12 In August 2020, No. 2020 06, Accounting for Convertible Instruments and Contracts in an Entity s Own Equity 2020 06 2020 06 2020 06 2020 06 December 15, 2021, December 15, 2023 2020 06

Note 2 - Liquidity

Note 2 - Liquidity	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Substantial Doubt about Going Concern [Text Block]	2. Liquidity The Company has been engaged in litigation with Platinum-Montaur Life Sciences LLC (“Platinum-Montaur”), an affiliate of Platinum Management (NY) LLC, Platinum Partners Value Arbitrage Fund L.P., Platinum Partners Capital Opportunity Fund, Platinum Partners Liquid Opportunity Master Fund L.P., Platinum Liquid Opportunity Management (NY) LLC, and Montsant Partners LLC (collectively, “Platinum”), in which Platinum-Montaur was seeking damages of approximately $1.9 13. In addition, the Company is engaged in ongoing litigation with our former President and Chief Executive Officer, Dr. Michael Goldberg. See Notes 9 13. The Company has also been engaged in ongoing litigation with Capital Royalty Partners II L.P. (“CRG”) and pursuing recovery of approximately $4.3 November 27, 2019, $4.3 April 9, 2018 ( March 16, 2021, 10th November 27, 2019 March 3, 2017 $4.3 not not 13. In June 2019, 8,000,000 $0.75 8,000,000 4,000,000 $0.75 4,000,000 $0.69375 $5,555,000. In December 2019, 2.1 $1.9 $1.1 2019, $812,000 December 31, 2019. $812,000 January 2020. In February 2020, two 4.0 $3.4 $3.4 first three 2020. 14. On May 6, 2020, 420,000 $4.2 $4.2 second third 2020. 14. On August 9, 2020, Tc99m $1.0 The MOU outlines certain terms that are expected to be included in the ELDA, including: ● Jubilant to provide Navidea with an additional $19.0 NAV3 32 2b NAV3 33 3 ● Jubilant will pay license fees and sales-based royalties to Navidea based on revenue generated from the sale of TRA in the licensed territory. ● Jubilant will serve as the exclusive commercial and distribution partner for TRA in the United States, Canada, Mexico, and Latin America. Jubilant will be responsible for all commercialization efforts within the licensed territory. The execution of the ELDA is subject to certain conditions, including negotiation of a definitive agreement in mutually acceptable form and Jubilant's completion of its due diligence. See Note 14. On August 30, 2020, $25.0 $0.001 10 $25,000 14. On August 31, 2020, 150,000 $15.0 one 5,147,000 10 $4.7 14 20 On March 2, 2021, 50,000 $5.0 2,173,913 20 Navidea intends to use the net proceeds from these transactions to fund its research and development programs, including continued advancement of its two 2b 3 Tc99m The Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) was enacted on March 27, 2020. 7 May 18, 2020, $366,000 February 23, 2021, $366,000 11. During the ongoing COVID- 19 not 19. 19 NAV3 32 19 February 2020 second third 2020, 19 The Company has experienced recurring net losses and has used significant cash to fund its operations. The Company has considerable discretion over the extent of development project expenditures and has the ability to curtail the related cash flows as needed. The Company also has funds remaining under outstanding grant awards, and continues working to establish new sources of funding, including collaborations, potential equity investments, and additional grant funding that can augment the balance sheet. Based on our committed equity investments, current working capital, and our projected cash burn, management believes that the Company will be able to continue as a going concern for at least twelve 10

Note 3 - Revenue From Contracts

Note 3 - Revenue From Contracts With Customers	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Revenue from Contract with Customer [Text Block]	3. Revenue from Contracts with Customers Navidea is focused on the development and commercialization of precision immunodiagnostic agents and immunotherapeutics. We manage our business based on two Tc99m Tc99m one Tc99 May 11, 2020, The Company also has an agreement in place to provide Meilleur Technologies, Inc. (“Meilleur”), a wholly-owned subsidiary of Cerveau Technologies, Inc., worldwide rights to conduct research using NAV4694, NAV4694 Currently, the Company recognizes revenue from up-front license fees and pre-market milestones after the cash has been received from its customers and the performance obligations have been met. Payments for sales-based royalties and milestones are generally received after the related revenue has been recognized and invoiced. Normal payment terms generally range from 15 90 Up-front and milestone payments received related to our license and distribution agreements in India and China are deferred until Tc99m not Tc99m not no not eight ten The transaction price of a contract is the amount of consideration to which the Company expects to be entitled in exchange for transferring promised goods or services to a customer. Transaction prices do not third not When estimating a contract's transaction price, the Company considers all the information (historical, current, and forecasted) that is reasonably available to it and identifies possible consideration amounts. Most of the Company's contracts with customers include both fixed and variable components of the transaction price. Under those contracts, some or all of the consideration for satisfied performance obligations is contingent on events over which the Company has no Tc99m The milestone payments have a binary outcome (that is, the Company will either receive all or none not Royalties are estimated based on the expected value method because they are based on a variable amount of sales representing a range of possible outcomes. However, when taking into account the constraint on variable consideration, the estimate of future royalties included in the transaction price is generally $0. Tc99m not no no The sublicense of NAV4694 No. 606, Revenue from Contracts with Customers 606” Up-front fees, milestones and royalties are generally non-refundable. Therefore, the Company does not During the years ended December 31, 2020 2019, $119,000 $38,000, December 31, 2020 2019, not The following table disaggregates the Company's revenue from contracts with customers for the years ended December 31, 2020 2019. Years Ended December 31, 2020 2019 Royalty revenue: Tc99m tilmanocept - Europe $ 7,995 $ 16,665 License revenue: Tc99m tilmanocept - Europe $ 110,730 $ — NAV4694 — 9,953 Total license revenue $ 110,730 $ 9,953 Other revenue: Additional stability studies $ — $ 11,024 The following economic factors affect the nature, amount, timing and uncertainty of the Company's revenue and cash flows as indicated: Geographical Location of Customers: may may Tc99m Status of Regulatory Approval: Tc99m Tc99m Tc99m not may NAV4694 not Through December 31, 2020, not The following table summarizes the changes in contract liabilities, the current portion of which is included in accrued liabilities and other in the consolidated balance sheets, during the years ended December 31, 2020 2019. Year Ended December 31, 2020 2019 Total deferred revenue, beginning of period $ 700,000 $ 711,024 Revenue deferred related to sublicense 160,000 495,000 Refund of deferred revenue related to sublicense (160,000 ) (495,000 ) Revenue recognized from satisfaction of performance obligations — (11,024 ) Total deferred revenue, end of period $ 700,000 $ 700,000 The Company had license revenue receivable of approximately $59,000 $0 December 31, 2020 2019, In addition to revenue from contracts from customers, we also generate revenue from National Institutes of Health (“NIH”) grants to support various product development initiatives. The revenue recognition standard applies to revenue from contracts with customers. A customer is defined as a party that has contracted with an entity to obtain goods or services that are an output of the entity's ongoing major or central operations in exchange for consideration. The Company's ongoing major or central operations consist of the development and commercialization of precision immunodiagnostic agents and immunotherapeutics. The NIH and its various institutes are responsible for biomedical and public health research and provide major biomedical research funding to non-NIH research facilities and entities such as Navidea. While the Company will directly benefit from any knowledge gained from the project, there is also a public health benefit provided, which justifies the use of public funds in the form of the grants. Based on the nature of the Company's operations and the terms of the grant awards, Navidea does not not December 31, 2020 2019, $696,000 $611,000, On May 11, 2020 ( March 5, 2015 ( Tc99m Pursuant to the Termination Agreement, the parties agreed that neither owed the other any payments due under the License Agreement as of the Termination Date and that, among other things, SpePharm will no six ninety

Note 4 - Stock-based Compensati

Note 4 - Stock-based Compensation	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Share-based Payment Arrangement [Text Block]	4. Stock-Based Compensation For the years ended December 31, 2020 2019, $231,000 $232,000, not December 31, 2020 2019. A summary of the status of our stock options as of December 31, 2020, Year Ended December 31, 2020 Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (years) Aggregate Intrinsic Value Outstanding, January 1, 2020 238,470 $ 17.38 Granted 315,000 2.29 Canceled and forfeited (3,000 ) 1.06 Expired (500 ) 30.80 Outstanding, December 31, 2020 549,970 $ 8.81 8.0 $ 209,280 Exercisable, December 31, 2020 119,870 $ 24.54 5.1 $ — The weighted average grant-date fair value of options granted in 2020 2019 $1.36 $1.65, No 2020 2019. 2020 2019 $0 A summary of the status of our unvested restricted stock as of December 31, 2020, Year Ended December 31, 2020 Number of Shares Weighted Average Grant-Date Fair Value Unvested, January 1, 2019 15,000 $ 2.75 Granted 60,000 2.90 Vested (15,000 ) 2.75 Unvested, December 31, 2019 60,000 $ 2.90 During 2020 2019, 15,000 5,000 $17,000 $14,000, 2020 2019, 15,000 5,000 $17,000 $14,000, As of December 31, 2020, $292,000 1.5 1

Note 5 - Loss Per Share

Note 5 - Loss Per Share	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Earnings Per Share [Text Block]	5. Loss Per Share Basic loss per share is calculated by dividing net loss attributable to common stockholders by the weighted-average number of common shares. Diluted loss per share reflects additional common shares that would have been outstanding if dilutive potential common shares had been issued. Potential common shares that may Diluted loss per common share for the years ended December 31, 2020 2019 1,111,744 1,487,681 The Company's unvested stock awards contain nonforfeitable rights to dividends or dividend equivalents, whether paid or unpaid (referred to as “participating securities”). Therefore, the unvested stock awards are required to be included in the number of shares outstanding for both basic and diluted earnings per share calculations. However, due to our loss from continuing operations, 60,000 15,000 December 31, 2020 2019,

Note 6 - Stock Subscriptions an

Note 6 - Stock Subscriptions and Other Receivables and Concentrations of Credit Risk	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Loans, Notes, Trade and Other Receivables Disclosure [Text Block]	6. Stock Subscriptions and Other Receivables and Concentrations of Credit Risk Stock subscriptions and other receivables at December 31, 2020 2019 2020 2019 Stock subscriptions $ 2,925,000 $ 811,946 License revenue 58,754 — Grant revenue 1,117 84,366 Other 2,448 5,027 Total stock subscriptions and other receivables $ 2,987,319 $ 901,339 At December 31, 2020 2019, 98% 90%, December 31, 2020 2019, no not 10 1

Note 7 - Inventory

Note 7 - Inventory	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Inventory Disclosure [Text Block]	7. Inventory The components of net inventory at December 31, 2020 2020 Materials $ 77,750 Finished goods 92,048 $ 169,798 During 2020, $11,000 2020, $39,000 1

Note 8 - Property and Equipment

Note 8 - Property and Equipment	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Property, Plant and Equipment Disclosure [Text Block]	8. Property and Equipment The major classes of property and equipment are as follows: Useful Life (years) 2020 2019 Purchased software 3 $ 320,435 $ 320,435 Production machinery and equipment 5 214,356 575,091 Other machinery and equipment, primarily computers and research equipment 3 – 5 297,315 296,987 Leasehold improvements* Term of Lease 12,448 12,448 Furniture and fixtures 7 825 2,576 Total property and equipment $ 845,379 $ 1,207,537 * We amortize leasehold improvements over the term of the lease, which in all cases is shorter than the estimated useful life of the asset. During 2020 2019, $34,000 $103,000, 1

Note 9 - Investment in Macropha

Note 9 - Investment in Macrophage Therapeutics, Inc.	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Investments in and Advances to Affiliates, Schedule of Investments [Text Block]	9. Investment in Macrophage Therapeutics, Inc. In March 2015, 50 1,500 $50,000 one 30 40% 50 may 1% March 11, 2015, first 10 300 $500,000. The warrants had certain characteristics including a net settlement provision that required the warrants to be accounted for as a derivative liability at fair value, with subsequent changes in fair value included in earnings. The fair value of the warrants was estimated to be $63,000 December 31, 2019, $0 March 2020 $2.0 $113,000 In addition, we entered into a Securities Exchange Agreement with the MT Investors providing them an option to exchange their MT Preferred Stock for our Common Stock in the event that MT has not $50 second $50,000 80% twenty second $60.00. not $58,320 In December 2015 May 2016, $200,000 not $200,000 In July 2016, $300,000 $200,000 10% $500 first $200,000 December 2015 May 2016. $200,000 10 not Goldberg Litigation In August 2018, one 1,175,000 1,175,000 18 5% November 2018, 925,000 250,000 On February 11, 2019, February 19, 2019, March 1, 2019, February 20, 2019, may December 18, 2020 no New York Litigation Involving Dr. Goldberg On February 20, 2019, April 26, 2019, June 13, 2019, third On December 26, 2019, third not The District Court also rejected Dr. Goldberg's claim for wrongful termination as Chief Executive Officer of MT. In addition, the District Court found that Dr. Goldberg lacked standing to seek injunctive relief to force the removal of Dr. Claudine Bruck and Michael Rice from MT's Board of Directors, to invalidate all actions taken by the MT Board on or after November 29, 2018 ( In addition, the District Court found Navidea's breach of fiduciary duty claim against Dr. Goldberg for conduct occurring more than three On January 31, 2020, April 1, 2020, On January 27, 2020, July 9, 2020, 1 2 3 4 On August 24, 2020, not third not Fact discovery in the New York Action has been completed and the parties and the Court anticipate meeting in the future to address remaining case deadlines. Delaware Litigation Involving Dr. Goldberg On February 20, 2019, June 12, 2019, not May 23, 2019 December 1 December 3, 2020. two one one March 16, 2021 Derivative Action Involving Dr. Goldberg On July 26, 2019, November 20, 2019, April 3, 2020, not 2 13.

Note 10 - Accounts Payable, Acc

Note 10 - Accounts Payable, Accrued Liabilities and Other	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]	10. Accounts Payable, Accrued Liabilities and Other Accounts payable at December 31, 2020 2019 $66,000 $65,000 December 31, 2020 2019 $755,000 $925,000, Accrued liabilities and other at December 31, 2020 2019 2020 2019 Contracted services $ 1,725,866 $ 1,212,347 Compensation 755,494 925,009 Other 31,634 13,618 Total accrued liabilities and other $ 2,512,994 $ 2,150,974

Note 11 - Notes Payable

Note 11 - Notes Payable	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Debt Disclosure [Text Block]	11. Notes Payable IPFS Corporation In November 2018, $393,000 5.1%. ten $40,000, August 2019. November 2020, $442,000 3.5%. seven $64,000, June 2021. Interest expense related to the IPFS notes payable totaled $1,000 $6,000 December 31, 2020 2019, $379,000 December 31, 2020, First Insurance Funding In November 2019, $349,000 5.0%. eight $44,000, July 2020. Interest expense related to the FIF note payable totaled $5,000 $1,000 December 31, 2020 2019, $306,000 December 31, 2019, Payroll Protection Program The CARES Act was enacted on March 27, 2020. 7 May 18, 2020, $366,000. 1% may eight twenty-four not ten May 12, 2021. May 1, 2022. February 23, 2021, $366,000 2. Summary During the years ended December 31, 2020 2019, $6,000 $8,000, $379,000 2021.

Note 12 - Leases

Note 12 - Leases	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Leases of Lessee Disclosure [Text Block]	12. Leases We currently lease approximately 5,000 4995 $3,000. June 2023. We also leased approximately 2,000 560 $3,000. March 31, 2019 not In addition, we currently lease approximately 25,000 5600 $27,000 2020. October 2022 five not June 2017, $39,000 October 2022. We also currently lease a vehicle at a monthly payment of approximately $300, September 2021, $100, October 2024. We adopted ASU 2016 02, Leases (Topic 842 January 1, 2019. 2016 02 January 1, 2019. Operating Lease Right- of-Use Assets Operating Lease Liabilities Terminated Lease Liability Deferred Rent Pre-adoption balance $ — $ — $ 589,173 $ 2,587 Change 406,842 998,602 (589,173 ) (2,587 ) Post-adoption balance $ 406,842 $ 998,602 $ — $ — An initial right-of-use lease asset of $407,000 2016 02. 2018. Total operating lease expense was $198,000 $229,000 December 31, 2020 2019, The following table presents information about the amount, timing and uncertainty of cash flows arising from the Company's operating leases as of December 31, 2020. Maturity of Lease Liabilities Operating Lease Payments 2021 $ 344,552 2022 291,111 2023 19,699 2024 1,355 Total undiscounted operating lease payments 656,717 Less imputed interest 65,760 Present value of operating lease liabilities $ 590,957 Balance Sheet Classification Current lease liabilities $ 294,951 Noncurrent lease liabilities 296,006 Total operating lease liabilities $ 590,957 Other Information Weighted-average remaining lease term for operating leases (years) 1.9 Weighted-average discount rate for operating leases 10.9 % Cash paid for amounts included in the present value of operating lease liabilities was $339,000 $330,000 December 31, 2020 2019, 1

Note 13 - Commitments and Conti

Note 13 - Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	13. Commitments and Contingencies We are subject to legal proceedings and claims that arise in the ordinary course of business. In accordance with ASC Topic 450, Contingencies not CRG Litigation The Company has been engaged in ongoing litigation with CRG, in its capacity as a lender and as control agent for other affiliated lenders party to the CRG Loan Agreement (collectively, the “CRG Lenders”), in the District Court of Harris County, Texas (the “Texas Court”) relating to CRG's claims of default under the terms the CRG Loan Agreement. Following a trial in December 2017, $66.0 $66.0 March 3, 2017. $59.0 March 2017, $7.0 not June 2016 $4.1 $66.0 $4.1 $4.1 $7.0 On April 9, 2018, $7.1 414, 414” $4.1 $59.0 The Company has also been engaged in ongoing litigation with CRG in the Court of Common Pleas of Franklin County, Ohio related to Navidea's claims that the CRG Lenders fraudulently induced Navidea to enter into a settlement agreement and breached the terms of the same through certain actions taken by the CRG Lenders in connection with the Global Settlement Agreement, pursuant to which Navidea agreed to pay up to $66.0 $66.0 $4.1 June 2016 $66.0 $66.0 $7.1 414 May 7, 2019, June 28, 2019. November 27, 2019, $66.0 $4.3 April 9, 2018, 414 no December 5, 2019, 10th March 27, 2020, September 23, 2020. March 16, 2021, 10th November 27, 2019 $4.3 not not CRG filed another lawsuit in the Texas Court in April 2018. not $7.1 414 August 28, 2020. December 18, 2020, February 1, 2021. 2. Platinum Litigation In November 2017, $1.9 March 3, 2017, October 31, 2018, no On November 30, 2018, January 22, 2019, September 5, 2019. November 25, 2019, not April 28, 2020 19 not June 4, 2020. September 2, 2020, September 23, 2020 not 2. Goldberg Agreement and Litigation In August 2018, one 1,175,000 1,175,000 18 5% November 2018, 925,000 250,000 On February 11, 2019, February 19, 2019, March 1, 2019, February 20, 2019, may December 18, 2020 no New York Litigation Involving Dr. Goldberg On February 20, 2019, April 26, 2019, June 13, 2019, third On December 26, 2019, third not The District Court also rejected Dr. Goldberg's claim for wrongful termination as Chief Executive Officer of MT. In addition, the District Court found that Dr. Goldberg lacked standing to seek injunctive relief to force the removal of Dr. Claudine Bruck and Michael Rice from MT's Board of Directors, to invalidate all actions taken by the MT Board on or after November 29, 2018 ( In addition, the District Court found Navidea's breach of fiduciary duty claim against Dr. Goldberg for conduct occurring more than three On January 31, 2020, April 1, 2020, On January 27, 2020, July 9, 2020, 1 2 3 4 On August 24, 2020, not third not Fact discovery in the New York Action has been completed and the parties and the Court anticipate meeting in the future to address remaining case deadlines. Delaware Litigation Involving Dr. Goldberg On February 20, 2019, June 12, 2019, not May 23, 2019 December 1 December 3, 2020. two one one March 16, 2021 Derivative Action Involving Dr. Goldberg On July 26, 2019, November 20, 2019, April 3, 2020, not 2 9. NYSE American Continued Listing Standards On August 14, 2018, not not 1003 $6.0 five 1003 The Company regained compliance with the minimum trading price standard following a one twenty April 26, 2019. On February 14, 2020, $6.0 1003 Even if an issuer has a stockholders' deficit, the NYSE American will not 1 $50,000,000; $50,000,000 two three 2 1,100,000 $15,000,000 400 December 31, 2020, $58.4 not may

Note 14 - Equity Instruments

Note 14 - Equity Instruments	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	14. Equity Instruments a. Preferred Stock and Common Stock: March 2019, $3.0 March 22, 2019, $50,000 $2.80 not June 15, 2019. No June 15, 2019 June 2019 In June 2019, 8,000,000 $0.75 8,000,000 4,000,000 $0.75 4,000,000 $0.69375 30 1,200,000 $0.69375. not 7.5% 1.0% $50,000 $100,000 $10,000 $5,555,000. $127,000 In December 2019, 2.1 $1.9 $1.1 2019, $812,000 December 31, 2019. $812,000 January 2020. $812,000 December 31, 2019. In February 2020, two 4.0 $3.4 $3.4 4,020,588 2020. On May 6, 2020, 420,000 $4.2 one November 6, 2020, 10% not 19.99% not $4.2 420,000 2020. $467,000 420,000 December 31, 2020. 1 420,000 1,425,076 2020. On August 9, 2020, Tc99m 209,205 $1.0 2. On August 30, 2020, $25.0 forty-five 45 1,000,000 $5.00 no ninety 90 $5.00 five 713 no $5.75 not ninety 90 not $25.0 ninety 90 no 4.99% $25,000 5,000 2020. $4.975 December 31, 2020. 2. On August 31, 2020, 150,000 $15.0 one nine 10% may not 19.99% not In the event of the liquidation or dissolution of the Company, after payment of the debts and other liabilities of the Company, the holders of Series D Preferred Stock then outstanding shall be entitled to receive, out of the assets of the Company and before any payment may x Of the $15.0 $1.8 17,750 2020. $197,000 17,750 2020. 1 17,750 827,280 2020. $2.9 29,250 January 1, 2021 10 29,250 1,375,089 January 1, 2021 10 $2.9 $10.3 December 31, 2020. 2 20 Navidea intends to use the net proceeds from these transactions to fund its research and development programs, including continued advancement of its two 2b 3 Tc99m 2. During the year ended December 31, 2020, 94,159 $172,000 2019 No December 31, 2019. During the years ended December 31, 2020 2019, 32,651 8,128 401 $40,000 $20,000, b. Stock Warrants: June 2019 600,000 7.5% five $0.9375 125% $261,000 88.6%, 1.8% $0. May 2020, 411,000 300,595 As of December 31, 2020, 992,000 $0.20 $49.80 $18.37. 0.2 14.6 The following table summarizes information about our outstanding warrants as of December 31, 2020. Exercise Price Number of Warrants Expiration Date Series HH $ 49.80 15,060 6/25/2023 Series KK 38.36 19,550 3/4/2021 Series LL 0.20 218,264 8/20/2035 Series NN 30.00 550,000 3/3/2022 Series OO 0.9375 189,000 6/13/2024 Total warrants $ 18.37 * 991,874 * Weighted average exercise price. In addition, 300 $2,000 March 2020. c. Common Stock Reserved: December 31, 2020, 1,541,844 995,000 August 2020 4,319,720 250,000 9 13.

Note 15 - Income Taxes

Note 15 - Income Taxes	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Income Tax Disclosure [Text Block]	15. Income Taxes As of December 31, 2020 2019, $45.8 $43.6 As of December 31, 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 34,365,098 $ 31,966,658 R&D credit carryforwards 9,301,709 9,150,580 AMT credit carryforward — 310,620 Stock compensation 419,654 382,016 Intangibles 616,926 610,783 Disallowed interest expense 852,338 857,648 Temporary differences 267,312 333,728 Deferred tax assets before valuation allowance 45,823,037 43,612,033 Valuation allowance (45,823,037 ) (43,301,413 ) Net deferred tax assets $ — $ 310,620 Current accounting standards require a valuation allowance against DTAs if, based on the weight of available evidence, it is more likely than not may not December 31, 2020 2019 In assessing the realizability of DTAs, management considers whether it is more likely than not not not not December 31, 2020. The Tax Cuts and Jobs Act (the “Tax Act”) was signed into law on December 22, 2017. 35% 21%, January 1, 2018. $26.4 $26.4 December 31, 2018. 2018, 2019 2020. may 2018 2020, 50% 2018, 2019 2020 2021. $621,000 December 31, 2019, 50% 50% December 31, 2019. March 27, 2020 $621,000 June 2020. no December 31, 2020. As of December 31, 2020 2019, $153.3 $142.2 $15.0 December 31, 2020, not December 31, 2017, 2016 09 As of December 31, 2020 2019, $20.1 2032. At December 31, 2020 2019, $8.9 $8.8 There were no 2020 2019. $72,000 $130,000 2020 2019, The details of our U.S. net operating loss and federal R&D credit carryforward amounts and expiration dates are summarized as follows: As of December 31, 2020 Generated Expiration U.S. Net Operating Loss Carryforwards U.S. R&D Credit Carryforwards 2001 2021 $ — $ 39,128 2002 2022 — 5,350 2003 2023 — 2,905 2004 2024 — 22,861 2005 2025 — 218,332 2006 2026 — 365,541 2007 2027 — 342,898 2008 2028 — 531,539 2009 2029 — 596,843 2010 2030 — 1,094,449 2011 2031 — 1,950,744 2012 2032 18,898,490 468,008 2013 2033 37,450,522 681,772 2014 2034 34,088,874 816,116 2015 2035 25,073,846 492,732 2016 2036 15,581,209 262,257 2017 2037 — 387,892 2018 2038 — 197,547 2019 N/A 11,245,808 213,065 2020 N/A 11,006,921 222,842 Total carryforwards $ 153,345,670 $ 8,912,821 Under Sections 382 383 1986, may 382 2020 382 Reconciliations between the statutory federal income tax rate and our effective tax rate for continuing operations are as follows: 2020 2019 Amount % Amount % Benefit at statutory rate $ (2,390,972 ) (21.0 )% $ (2,299,122 ) (21.0 )% Adjustments to valuation allowance 2,521,625 22.1 % 2,355,947 15.3 % Adjustments to R&D credit carryforwards (151,129 ) (1.3 )% (82,706 ) 6.1 % Permanent items and other 20,476 0.2 % 26,588 0.3 % Provision (benefit) per financial statements $ — $ 707 See Note 1

Note 16 - Segments

Note 16 - Segments	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	16. Segments We report information about our operating segments using the “management approach” in accordance with current accounting standards. This information is based on the way management organizes and reports the segments within the enterprise for making operating decisions and assessing performance. Our reportable segments are identified based on differences in products, services and markets served. There were no two Tc99m The information in the following tables is derived directly from each reportable segment's financial reporting. Year Ended December 31, 2020 Diagnostics Therapeutics Corporate Total Royalty revenue $ 7,995 $ — $ — $ 7,995 License revenue 110,730 — — 110,730 Grant and other revenue 482,221 314,067 — 796,288 Total revenue 600,946 314,067 — 915,013 Cost of revenue 1,048 — — 1,048 Research and development expenses 4,593,459 336,728 — 4,930,187 Selling, general and administrative expenses, excluding depreciation and amortization (1) 299,959 800 6,323,807 6,624,566 Depreciation and amortization (2) 10,068 — 60,325 70,393 Loss from operations (3) (4,303,588 ) (23,461 ) (6,384,132 ) (10,711,181 ) Other expense (4) — — (10,510 ) (10,510 ) Net loss (4,303,588 ) (23,461 ) (6,394,642 ) (10,721,691 ) Total assets, net of depreciation and amortization: United States $ 139,121 — 7,416,106 7,555,227 International 202,791 — — 202,791 Capital expenditures 120,810 — 15,071 135,881 Year Ended December 31, 2019 Diagnostics Therapeutics Corporate Total Royalty revenue $ 16,665 $ — $ — $ 16,665 License revenue 9,953 — — 9,953 Grant and other revenue 384,776 246,432 — 631,208 Total revenue 411,394 246,432 — 657,826 Cost of revenue 6,667 — — 6,667 Research and development expenses, excluding depreciation and amortization 4,795,445 542,822 — 5,338,267 Selling, general and administrative expenses, excluding depreciation and amortization (1) — 16,990 6,113,907 6,130,897 Depreciation and amortization (2) — — 144,512 144,512 Loss from operations (3) (4,390,718 ) (313,380 ) (6,258,419 ) (10,962,517 ) Other income (4) — — 17,675 17,675 Provision for income taxes (284 ) (20 ) (403 ) (707 ) Loss from continuing operations (4,391,002 ) (313,400 ) (6,241,147 ) (10,945,549 ) Loss from discontinued operations, net of tax effect (2,665 ) — — (2,665 ) Net loss (4,393,666 ) (313,400 ) (6,241,147 ) (10,948,214 ) Total assets, net of depreciation and amortization: United States $ 55,229 $ 31,449 $ 4,064,228 $ 4,150,906 International — — — — Capital expenditures — — 1,258 1,258 ( 1 General and administrative expenses, excluding depreciation and amortization, represent costs that relate to the general administration of the Company and as such are not ( 2 Depreciation and amortization are reflected in selling, general and administrative expenses ( $70,393 $144,512 December 31, 2020 2019, ( 3 Loss from operations does not ( 4 Amounts consist primarily of interest income and interest expense, which are not

Note 17 - Material Agreements

Note 17 - Material Agreements	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Significant Agreements Disclosure [Text Block]	17. Material Agreements a. License Agreements: January 2002, Tc99m July 2014, third $25,000 $25,000 $25,000 In connection with the March 2017 414, Tc99m 414 414 414 Tc99m Tc99m $1,000 $2,000 2020 2019, $34,000 $191,000 2020 2019, In July 2014, Tc99m third may $25,000 $25,000 $25,000 $275,000 $355,000 2020 2019, b. Employment Agreements: December 31, 2020, one five December 31, 2020, $2.5

Note 18 - Employee Benefit Plan

Note 18 - Employee Benefit Plan	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Compensation and Employee Benefit Plans [Text Block]	18. Employee Benefit Plan We maintain an employee benefit plan under Section 401 may, not 401 $49,000 $14,000 2020 2019,

Note 19 - Supplemental Disclosu

Note 19 - Supplemental Disclosure for Statements of Cash Flows	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Cash Flow, Supplemental Disclosures [Text Block]	19. Supplemental Disclosure for Statements of Cash Flows We paid interest aggregating $6,000 $8,000 2020 2019, February 2020, $100,432. January 1, 2019, 2016 02, Leases (Topic 842 $407,000 2020, 94,159 $172,000 2019 2020 2019, 32,651 8,128 401 $40,000 $20,000, November 2020, $442,000 3.5%. November 2019, $349,000 5.0%. 2020, 411,000 300,595 2020, $467,000 420,000 420,000 1,425,076 2020, $197,000 17,750 17,750 827,280

Note 20 - Subsequent Events

Note 20 - Subsequent Events	12 Months Ended
	Dec. 31, 2020
Notes to Financial Statements
Subsequent Events [Text Block]	20. Subsequent Events The Company has evaluated events and transactions subsequent to December 31, 2020 10 a. Series D Preferred Stock: August 31, 2020, 150,000 $15.0 $1.8 17,750 2020. 17,750 827,280 2020. $2.9 29,250 January 1, 2021 10 29,250 1,375,089 January 1, 2021 10 $2.9 $10.3 December 31, 2020. 2 14. b. Series E Preferred Stock: March 2, 2021, 50,000 $5.0 2,173,913 2.

Significant Accounting Policies

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Nature of Operations [Policy Text Block]	a. Organization and Nature of Operations: Navidea's Manocept platform is predicated on the ability to specifically target the CD206 Tc99m first Tc99m none In July 2011, Tc99m 100% In January 2015, 99.9% In June 2020, 100% On April 26, 2019, one twenty $.001 twenty one 201.0 10.1 not 300.0 $0.001 January 1, 2019. not
Consolidation, Policy [Policy Text Block]	b. Principles of Consolidation:
Use of Estimates, Policy [Policy Text Block]	c. Use of Estimates:
Fair Value of Financial Instruments, Policy [Policy Text Block]	d. Financial Instruments and Fair Value: ( 1 Cash and cash equivalents, stock subscriptions and other receivables, and accounts payable: ( 2 Notes payable: December 31, 2020 2019 December 31, 2020 2019, $745,000 $306,000, 11. ( 3 Warrants: June 2019, 600,000 7.5% $261,000 88.6%, 1.8% $0. 14
Share-based Payment Arrangement [Policy Text Block]	e. Stock-Based Compensation: December 31, 2020, two 2002 “2002 2014 “2014 2014 may may 2014 1,750,000 2002 no may Stock options granted under the 2002 2014 one four not ten 90 Stock-based payments to employees and directors, including grants of stock options and restricted stock, are recognized in the statements of operations based on their estimated fair values on the date of grant, subject to an estimated forfeiture rate. The fair value of each option award with time-based vesting provisions is estimated on the date of grant using the Black-Scholes option pricing model. The determination of fair value using the Black-Scholes option pricing model is affected by our stock price as well as assumptions regarding a number of complex and subjective variables, including expected stock price volatility, risk-free interest rate, expected dividends and projected employee stock option behaviors. The fair value of each option award with market-based vesting provisions is estimated on the date of grant using a Monte Carlo simulation. The determination of fair value using a Monte Carlo simulation is affected by our stock price as well as assumptions regarding a number of complex and subjective variables, including expected stock price volatility, risk-free interest rate, expected dividends and projected employee stock option behaviors. Expected volatilities are based on the Company's historical volatility, which management believes represents the most accurate basis for estimating expected future volatility under the current circumstances. Navidea uses historical data to estimate forfeiture rates. The expected term of stock options granted is based on the vesting period and the contractual life of the options. The risk-free rate is based on the U.S. Treasury yield in effect at the time of the grant. The assumptions used to calculate the fair value of stock option awards granted during the years ended December 31, 2020 2019 2020 2019 Expected volatility 86% - 102% 76% - 93% Weighted-average volatility 92% 86% Expected forfeiture rate 7.0% - 10.5% 15.1% - 15.5% Expected term (in years) 5.5 - 6.0 3.5 - 6.0 Risk-free rate 0.4% - 1.5% 2.4% - 2.5% Expected dividends — — The portion of the fair value of stock-based awards that is ultimately expected to vest is recognized as compensation expense over either ( 1 2 may not not 4.
Cash and Cash Equivalents, Policy [Policy Text Block]	f. Cash and Cash Equivalents: three
Receivable [Policy Text Block]	g. Stock Subscriptions and Other Receivables: 6.
Inventory, Policy [Policy Text Block]	h. Inventory: first first 7.
Property, Plant and Equipment, Policy [Policy Text Block]	i. Property and Equipment: 8.
Intangible Assets, Finite-Lived, Policy [Policy Text Block]	j. Intangible Assets: 5 15 no 2020 2019, $278,000 $57,000, 2020 2019, $9,000 $58,000,
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	k. Impairment or Disposal of Long-Lived Assets: may not No December 31, 2020 2019.
Lessee, Leases [Policy Text Block]	l. Leases: 2018. 12 not 12.
Revenue [Policy Text Block]	m. Revenue Recognition: We also earn revenues related to our licensing and distribution agreements. The consideration we are eligible to receive under our licensing and distribution agreements typically includes upfront payments, reimbursement for research and development costs, milestone payments, and royalties. Each licensing and distribution agreement is unique and requires separate assessment in accordance with current accounting standards. See Note 3.
Research and Development Expense, Policy [Policy Text Block]	n. Research and Development Costs:
Income Tax, Policy [Policy Text Block]	o. Income Taxes: December 31, 2020 2019. Current accounting standards include guidance on the accounting for uncertainty in income taxes recognized in the financial statements. Such standards also prescribe a recognition threshold and measurement model for the financial statement recognition of a tax position taken, or expected to be taken, and provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, disclosure and transition. The Company believes that the ultimate deductibility of all tax positions is highly certain, although there is uncertainty about the timing of such deductibility. As a result, no December 31, 2020 2019 not twelve December 31, 2020, 2017 2020 15.
Stockholders' Equity Note, Redeemable Preferred Stock, Issue, Policy [Policy Text Block]	p. Series C and Series D Convertible Preferred Stock: 480, Distinguishing Liabilities from Equity 815, Derivatives and Hedging 470, Debt 268, Presentation in Financial Statements of Redeemable Preferred Stocks not not not 14.
New Accounting Pronouncements, Policy [Policy Text Block]	q. Recently Adopted Accounting Standards: February 2016, No. 2016 02, Leases (Topic 842 2016 02 842 In July 2018, No. 2018 10, Codification Improvements to Topic 842, No. 2018 11, Targeted Improvements to Topic 842, 2018 10 842 2016 02, Leases (Topic 842 2018 11 840, Leases 840 840. 2018 10 2018 11 2016 02 December 15, 2018. The Company adopted ASU 2016 02, 2018 10 2018 11 January 1, 2019 not 12 The adoption of ASU 2016 02 $407,000 January 1, 2019 2016 02 not 12. In June 2018, No. 2018 07, Compensation Stock Compensation (Topic 718 2018 07 718 718 2018 07 718 718 not 1 2 606, Revenue from Contracts with Customers 2018 07 December 15, 2018, 2018 07 not In July 2018, No. 2018 09, Codification Improvements 2018 09 2018 09 December 15, 2018 2018 09 not In August 2018, No. 2018 13, Fair Value Measurement (Topic 820 Disclosure Framework Changes to the Disclosure Requirements for Fair Value Measurement 2018 13 820. 2018 13 December 15, 2019. 2018 13 not r. Recently Issued Accounting Standards: December 2019, No. 2019 12, Income Taxes (Topic 740 2019 12 2019 12 740 2019 12 December 12, 2020, not 2019 12 In August 2020, No. 2020 06, Accounting for Convertible Instruments and Contracts in an Entity s Own Equity 2020 06 2020 06 2020 06 2020 06 December 15, 2021, December 15, 2023 2020 06

Note 1 - Organization and Sum_2

Note 1 - Organization and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	2020 2019 Expected volatility 86% - 102% 76% - 93% Weighted-average volatility 92% 86% Expected forfeiture rate 7.0% - 10.5% 15.1% - 15.5% Expected term (in years) 5.5 - 6.0 3.5 - 6.0 Risk-free rate 0.4% - 1.5% 2.4% - 2.5% Expected dividends — —

Note 3 - Revenue From Contrac_2

Note 3 - Revenue From Contracts With Customers (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Disaggregation of Revenue [Table Text Block]	Years Ended December 31, 2020 2019 Royalty revenue: Tc99m tilmanocept - Europe $ 7,995 $ 16,665 License revenue: Tc99m tilmanocept - Europe $ 110,730 $ — NAV4694 — 9,953 Total license revenue $ 110,730 $ 9,953 Other revenue: Additional stability studies $ — $ 11,024
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]	Year Ended December 31, 2020 2019 Total deferred revenue, beginning of period $ 700,000 $ 711,024 Revenue deferred related to sublicense 160,000 495,000 Refund of deferred revenue related to sublicense (160,000 ) (495,000 ) Revenue recognized from satisfaction of performance obligations — (11,024 ) Total deferred revenue, end of period $ 700,000 $ 700,000

Note 4 - Stock-based Compensa_2

Note 4 - Stock-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Share-based Payment Arrangement, Option, Activity [Table Text Block]	Year Ended December 31, 2020 Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (years) Aggregate Intrinsic Value Outstanding, January 1, 2020 238,470 $ 17.38 Granted 315,000 2.29 Canceled and forfeited (3,000 ) 1.06 Expired (500 ) 30.80 Outstanding, December 31, 2020 549,970 $ 8.81 8.0 $ 209,280 Exercisable, December 31, 2020 119,870 $ 24.54 5.1 $ —
Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]	Year Ended December 31, 2020 Number of Shares Weighted Average Grant-Date Fair Value Unvested, January 1, 2019 15,000 $ 2.75 Granted 60,000 2.90 Vested (15,000 ) 2.75 Unvested, December 31, 2019 60,000 $ 2.90

Note 6 - Stock Subscriptions _2

Note 6 - Stock Subscriptions and Other Receivables and Concentrations of Credit Risk (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]	2020 2019 Stock subscriptions $ 2,925,000 $ 811,946 License revenue 58,754 — Grant revenue 1,117 84,366 Other 2,448 5,027 Total stock subscriptions and other receivables $ 2,987,319 $ 901,339

Note 7 - Inventory (Tables)

Note 7 - Inventory (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Schedule of Inventory, Current [Table Text Block]	2020 Materials $ 77,750 Finished goods 92,048 $ 169,798

Note 8 - Property and Equipme_2

Note 8 - Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Property, Plant and Equipment [Table Text Block]	Useful Life (years) 2020 2019 Purchased software 3 $ 320,435 $ 320,435 Production machinery and equipment 5 214,356 575,091 Other machinery and equipment, primarily computers and research equipment 3 – 5 297,315 296,987 Leasehold improvements* Term of Lease 12,448 12,448 Furniture and fixtures 7 825 2,576 Total property and equipment $ 845,379 $ 1,207,537

Note 10 - Accounts Payable, A_2

Note 10 - Accounts Payable, Accrued Liabilities and Other (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Schedule of Accrued Liabilities [Table Text Block]	2020 2019 Contracted services $ 1,725,866 $ 1,212,347 Compensation 755,494 925,009 Other 31,634 13,618 Total accrued liabilities and other $ 2,512,994 $ 2,150,974

Note 12 - Leases (Tables)

Note 12 - Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Maturity of Lease Liabilities Operating Lease Payments 2021 $ 344,552 2022 291,111 2023 19,699 2024 1,355 Total undiscounted operating lease payments 656,717 Less imputed interest 65,760 Present value of operating lease liabilities $ 590,957
Lessee, Operating Lease, Assets and Liabilities [Table Text Block]	Balance Sheet Classification Current lease liabilities $ 294,951 Noncurrent lease liabilities 296,006 Total operating lease liabilities $ 590,957
Lease, Cost [Table Text Block]	Other Information Weighted-average remaining lease term for operating leases (years) 1.9 Weighted-average discount rate for operating leases 10.9 %
Accounting Standards Update 2016-02 [Member]
Notes Tables
Accounting Standards Update and Change in Accounting Principle [Table Text Block]	Operating Lease Right- of-Use Assets Operating Lease Liabilities Terminated Lease Liability Deferred Rent Pre-adoption balance $ — $ — $ 589,173 $ 2,587 Change 406,842 998,602 (589,173 ) (2,587 ) Post-adoption balance $ 406,842 $ 998,602 $ — $ —

Note 14 - Equity Instruments (T

Note 14 - Equity Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Schedule of Stockholders' Equity Note, Warrants or Rights [Table Text Block]	Exercise Price Number of Warrants Expiration Date Series HH $ 49.80 15,060 6/25/2023 Series KK 38.36 19,550 3/4/2021 Series LL 0.20 218,264 8/20/2035 Series NN 30.00 550,000 3/3/2022 Series OO 0.9375 189,000 6/13/2024 Total warrants $ 18.37 * 991,874

Note 15 - Income Taxes (Tables)

Note 15 - Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	As of December 31, 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 34,365,098 $ 31,966,658 R&D credit carryforwards 9,301,709 9,150,580 AMT credit carryforward — 310,620 Stock compensation 419,654 382,016 Intangibles 616,926 610,783 Disallowed interest expense 852,338 857,648 Temporary differences 267,312 333,728 Deferred tax assets before valuation allowance 45,823,037 43,612,033 Valuation allowance (45,823,037 ) (43,301,413 ) Net deferred tax assets $ — $ 310,620
Summary of Tax Credit Carryforwards [Table Text Block]	As of December 31, 2020 Generated Expiration U.S. Net Operating Loss Carryforwards U.S. R&D Credit Carryforwards 2001 2021 $ — $ 39,128 2002 2022 — 5,350 2003 2023 — 2,905 2004 2024 — 22,861 2005 2025 — 218,332 2006 2026 — 365,541 2007 2027 — 342,898 2008 2028 — 531,539 2009 2029 — 596,843 2010 2030 — 1,094,449 2011 2031 — 1,950,744 2012 2032 18,898,490 468,008 2013 2033 37,450,522 681,772 2014 2034 34,088,874 816,116 2015 2035 25,073,846 492,732 2016 2036 15,581,209 262,257 2017 2037 — 387,892 2018 2038 — 197,547 2019 N/A 11,245,808 213,065 2020 N/A 11,006,921 222,842 Total carryforwards $ 153,345,670 $ 8,912,821
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	2020 2019 Amount % Amount % Benefit at statutory rate $ (2,390,972 ) (21.0 )% $ (2,299,122 ) (21.0 )% Adjustments to valuation allowance 2,521,625 22.1 % 2,355,947 15.3 % Adjustments to R&D credit carryforwards (151,129 ) (1.3 )% (82,706 ) 6.1 % Permanent items and other 20,476 0.2 % 26,588 0.3 % Provision (benefit) per financial statements $ — $ 707

Note 16 - Segments (Tables)

Note 16 - Segments (Tables)	12 Months Ended
	Dec. 31, 2020
Notes Tables
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Year Ended December 31, 2020 Diagnostics Therapeutics Corporate Total Royalty revenue $ 7,995 $ — $ — $ 7,995 License revenue 110,730 — — 110,730 Grant and other revenue 482,221 314,067 — 796,288 Total revenue 600,946 314,067 — 915,013 Cost of revenue 1,048 — — 1,048 Research and development expenses 4,593,459 336,728 — 4,930,187 Selling, general and administrative expenses, excluding depreciation and amortization (1) 299,959 800 6,323,807 6,624,566 Depreciation and amortization (2) 10,068 — 60,325 70,393 Loss from operations (3) (4,303,588 ) (23,461 ) (6,384,132 ) (10,711,181 ) Other expense (4) — — (10,510 ) (10,510 ) Net loss (4,303,588 ) (23,461 ) (6,394,642 ) (10,721,691 ) Total assets, net of depreciation and amortization: United States $ 139,121 — 7,416,106 7,555,227 International 202,791 — — 202,791 Capital expenditures 120,810 — 15,071 135,881 Year Ended December 31, 2019 Diagnostics Therapeutics Corporate Total Royalty revenue $ 16,665 $ — $ — $ 16,665 License revenue 9,953 — — 9,953 Grant and other revenue 384,776 246,432 — 631,208 Total revenue 411,394 246,432 — 657,826 Cost of revenue 6,667 — — 6,667 Research and development expenses, excluding depreciation and amortization 4,795,445 542,822 — 5,338,267 Selling, general and administrative expenses, excluding depreciation and amortization (1) — 16,990 6,113,907 6,130,897 Depreciation and amortization (2) — — 144,512 144,512 Loss from operations (3) (4,390,718 ) (313,380 ) (6,258,419 ) (10,962,517 ) Other income (4) — — 17,675 17,675 Provision for income taxes (284 ) (20 ) (403 ) (707 ) Loss from continuing operations (4,391,002 ) (313,400 ) (6,241,147 ) (10,945,549 ) Loss from discontinued operations, net of tax effect (2,665 ) — — (2,665 ) Net loss (4,393,666 ) (313,400 ) (6,241,147 ) (10,948,214 ) Total assets, net of depreciation and amortization: United States $ 55,229 $ 31,449 $ 4,064,228 $ 4,150,906 International — — — — Capital expenditures — — 1,258 1,258

Note 1 - Organization and Sum_3

Note 1 - Organization and Summary of Significant Accounting Policies (Details Textual)	Apr. 26, 2019$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Jun. 30, 2019shares	Apr. 25, 2019shares	Jan. 01, 2019USD ($)
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares	$ 0.001	$ 0.001	$ 0.001
Common Stock, Shares, Outstanding, Ending Balance (in shares) | shares	10,100,000	27,149,691	19,234,960		201,000,000
Common Stock, Shares Authorized (in shares) | shares	300,000,000	300,000,000	300,000,000
Notes Payable, Fair Value Disclosure		$ 745,000	$ 306,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares		992,000
Patent and Trademark Costs		$ 277,989	56,700
Previously Capitalized Patent Costs Abandoned		9,000	58,000
Impairment of Long-Lived Assets to be Disposed of		0	0
Unrecognized Tax Benefits, Ending Balance		$ 0	0
Open Tax Year		2017 2018 2019 2020
Operating Lease, Right-of-Use Asset		$ 250,095	$ 281,688			$ 406,842
Operating Lease, Liability, Total		$ 590,957				998,602
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset						407,000
Operating Lease, Liability, Total						$ 407,000
Minimum [Member]
Finite-Lived Intangible Asset, Useful Life (Year)		5 years
Maximum [Member]
Finite-Lived Intangible Asset, Useful Life (Year)		15 years
The 2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | shares		1,750,000
The 2002 and 2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)		10 years
The 2002 and 2014 Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)		1 year
The 2002 and 2014 Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)		4 years
Underwriting Agreement Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares				600,000
Class of Warrant or Right Percent of Common Stock Sold				7.50%
Warrants and Rights Outstanding		$ 261,000
Underwriting Agreement Warrants [Member] | Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input		0.886
Underwriting Agreement Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants and Rights Outstanding, Measurement Input		0.018
Underwriting Agreement Warrants [Member] | Measurement Input, Expected Dividend Payment [Member]
Warrants and Rights Outstanding, Measurement Input		0
Reverse Stock Split [Member]
Stockholders' Equity Note, Stock Split, Conversion Ratio	20
Navidea Biopharmaceuticals Limited [Member]
Noncontrolling Interest, Ownership Percentage by Parent		100.00%
Macrophage Therapeutics [Member]
Noncontrolling Interest, Ownership Percentage by Parent		99.90%
Navidea Europe [Member]
Noncontrolling Interest, Ownership Percentage by Parent		100.00%

Note 1 - Organization and Sum_4

Note 1 - Organization and Summary of Significant Accounting Policies - Assumptions Used to Calculate Fair Value of Stock Option Awards Granted (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Expected volatility, minimum	86.00%	76.00%
Expected volatility, maximum	102.00%	93.00%
Weighted-average volatility	92.00%	86.00%
Risk-free rate, minimum	0.40%	2.40%
Risk-free rate, maximum	1.50%	2.50%
Expected dividends
Minimum [Member]
Expected forfeiture rate	7.00%
Expected forfeiture rate		15.10%
Expected term (Year)	5 years 182 days	3 years 182 days
Maximum [Member]
Expected forfeiture rate	10.50%
Expected forfeiture rate		15.50%
Expected term (Year)	6 years	6 years

Note 2 - Liquidity (Details Tex

Note 2 - Liquidity (Details Textual)	Mar. 16, 2021USD ($)	Mar. 02, 2021USD ($)shares	Feb. 23, 2021USD ($)	Aug. 31, 2020USD ($)shares	Aug. 30, 2020USD ($)$ / sharesshares	Aug. 09, 2020USD ($)shares	May 18, 2020USD ($)	May 06, 2020USD ($)shares	Nov. 27, 2019USD ($)	Mar. 22, 2019USD ($)$ / shares	Feb. 29, 2020USD ($)shares	Jan. 31, 2020USD ($)	Dec. 31, 2019USD ($)$ / shares	Jun. 30, 2019USD ($)$ / sharesshares	Nov. 30, 2017USD ($)	Jan. 31, 2020USD ($)shares	Mar. 25, 2021USD ($)shares	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)$ / shares	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / shares	Apr. 26, 2019$ / shares
Stock Issued During Period, Shares, New Issues (in shares) | shares																2,100,000
Proceeds from Issuance of Common Stock												$ 812,000	$ 1,100,000			$ 1,900,000					$ 4,442,560	$ 7,086,915
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable																			$ 4,975,000		4,975,000
Stock Issued During Period, Value, New Issues																					1,250,000	5,166,441
Proceeds from Issuance of Preferred Stock and Preference Stock																					$ 5,975,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares													$ 0.001						$ 0.001		$ 0.001	$ 0.001	$ 0.001
Proceeds from Notes Payable, Total																					$ 366,000
Paycheck Protection Program CARES Act [Member]
Proceeds from Notes Payable, Total							$ 366,000
Series C Preferred Stock [Member]
Stock Issued During Period, Value, New Issues																					4,163,178
Series D Preferred Stock [Member]
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable																			$ 2,900,000		2,900,000
Stock Issued During Period, Value, New Issues																					$ 132,107
Investor [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares											4,000,000										4,020,588
Proceeds from Issuance of Common Stock											$ 3,400,000									$ 3,400,000
Accounts and Other Receivables [Member]
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable													$ 812,000									812,000
Keystone Capital Partners, LLC [Member] | Series C Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares								420,000			420,000										420,000
Proceeds from Issuance of Common Stock																					$ 4.20
Stock Issued During Period, Value, New Issues								$ 4,200,000			$ 4,200,000
Proceeds from Issuance of Preferred Stock and Preference Stock																			4,200,000
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares				150,000																	17,750
Stock Issued During Period, Value, New Issues				$ 15,000,000
Proceeds from Issuance of Preferred Stock and Preference Stock																					$ 1,800,000
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member] | Maximum [Member]
Convertible Preferred Stock, Shares Issued upon Conversion (in shares) | shares				5,147,000
Jubilant [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares						209,205
Proceeds from Issuance of Common Stock						$ 1,000,000
Underwritten Public Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares														8,000,000
Shares Issued, Price Per Share (in dollars per share) | $ / shares														$ 0.75
Proceeds from Issuance of Common Stock														$ 5,555,000
Underwritten Public Offering [Member] | John K. Scott, Jr. [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares														4,000,000
Shares Issued, Price Per Share (in dollars per share) | $ / shares														$ 0.75
Underwritten Public Offering [Member] | Underwriter [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares														4,000,000
Shares Issued, Price Per Share (in dollars per share) | $ / shares														$ 0.69375
Private Placement [Member]
Shares Issued, Price Per Share (in dollars per share) | $ / shares										$ 2.80
Stock Issued During Period, Value, New Issues										$ 50,000											$ 2,059	$ 1,090,000
Private Placement [Member] | Investor [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares																					5,000
Sale of Stock, Commitment Amount					$ 25,000
Private Placement [Member] | Jubilant [Member]
Sale of Stock, Commitment Amount						1,000,000
Sale of Stock, Additional Milestone Commitment Amount						$ 19,000,000
Private Placement [Member] | Mastiff Group LLC [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares					1,000,000
Shares Issued, Price Per Share (in dollars per share) | $ / shares					$ 5
Sale of Stock, Commitment Amount					$ 25,000,000														$ 4,975,000		$ 4,975,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares					$ 0.001
Private Placement [Member] | Mastiff Group LLC [Member] | Maximum [Member]
Shares Issued, Price Per Share (in dollars per share) | $ / shares					$ 5.75
Subsequent Event [Member] | Paycheck Protection Program CARES Act [Member]
Forgiveness of Notes Payable			$ 366,000
Subsequent Event [Member] | John K. Scott, Jr. [Member] | Series E Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares		50,000
Stock Issued During Period, Value, New Issues		$ 5,000,000
Debt Instrument, Convertible, Number of Equity Instruments		2,173,913
Subsequent Event [Member] | Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares																	29,250
Proceeds from Issuance of Common Stock																	$ 4,700,000
Proceeds from Issuance of Preferred Stock and Preference Stock																	2,900,000
Subsequent Event [Member] | Private Placement [Member] | Mastiff Group LLC [Member]
Proceeds from Issuance of Common Stock																	$ 25,000
Platinum-Montaur Life Sciences LLC Litigation [Member]
Loss Contingency, Damages Sought, Value															$ 1,900,000
CRG Loan Agreement, Ohio Case [Member]
Loss Contingency, Damages Sought, Value																		$ 4,300,000
Ohio Court of Common Pleas [Member]
Litigation Settlement, Amount Awarded from Other Party									$ 4,300,000
Ohio Court of Common Pleas [Member] | Subsequent Event [Member]
Litigation Settlement, Reversal of Amount Awarded from Other Party	$ 4,300,000

Note 3 - Revenue From Contrac_3

Note 3 - Revenue From Contracts With Customers (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Contract with Customer, Payment Term, Minimum (Day)	15 days
Contract with Customer, Payment Term, Maximum (Day)	90 days
Contract with Customer, Transaction Price of Royalties Using Expected Value Method	$ 0
Revenue from Contract with Customer, Including Assessed Tax	119,000	$ 38,000
Contract with Customer, Asset, Impairment Loss	0	0
Capitalized Contract Cost, Net, Total	0
Contract with Customer, Asset, after Allowance for Credit Loss, Total	59,000	0
Grant [Member]
Revenue Not from Contract with Customer	$ 696,000	$ 611,000
INDIA
Contract with Customer, Term of Contract (Year)	8 years
CHINA
Contract with Customer, Term of Contract (Year)	10 years

Note 3 - Revenue From Contrac_4

Note 3 - Revenue From Contracts With Customers - Disaggregation of Revenue (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue from contract with customer	$ 119,000	$ 38,000
Royalty [Member]
Revenue from contract with customer	7,995	16,665
License [Member]
Revenue from contract with customer	110,730	9,953
Diagnostics Segment [Member] | Royalty [Member]
Revenue from contract with customer	7,995	16,665
Diagnostics Segment [Member] | Royalty [Member] | Europe [Member]
Revenue from contract with customer	7,995	16,665
Diagnostics Segment [Member] | Expanded Tc99m Tilmanocept License Agreement [Member] | Europe [Member]
Revenue from contract with customer	110,730
Diagnostics Segment [Member] | NAV4694 Sublicense [Member]
Revenue from contract with customer		9,953
Diagnostics Segment [Member] | License [Member]
Revenue from contract with customer	110,730	9,953
Diagnostics Segment [Member] | Product and Service, Other [Member]
Revenue from contract with customer		$ 11,024

Note 3 - Revenue From Contrac_5

Note 3 - Revenue From Contracts With Customers - Changes in Contract Liabilities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Total deferred revenue, beginning of period	$ 700,000	$ 711,024
Revenue deferred related to sublicense	160,000	495,000
Refund of deferred revenue related to sublicense	(160,000)	(495,000)
Revenue recognized from satisfaction of performance obligations		(11,024)
Total deferred revenue, end of period	$ 700,000	$ 700,000

Note 4 - Stock-based Compensa_3

Note 4 - Stock-based Compensation (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement, Expense	$ 231,000	$ 232,000
Share-based Payment Arrangement, Expense, Tax Benefit	$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)	$ 1.36	$ 1.65
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	$ 0	$ 0
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 292,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)	1 year 182 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares)	15,000	5,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value	$ 17,000	$ 14,000
Restricted Stock [Member] | Director [Member] | Vesting As Scheduled [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value	$ 17,000	$ 14,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period (in shares)	15,000	5,000

Note 4 - Stock-based Compensa_4

Note 4 - Stock-based Compensation - Summary of Stock Option Activity (Details)	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Outstanding at beginning of period (in shares) | shares	238,470
Outstanding at beginning of period, weighted average exercise price (in dollars per share) | $ / shares	$ 17.38
Granted (in shares) | shares	315,000
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 2.29
Canceled and forfeited (in shares) | shares	(3,000)
Canceled and Forfeited, weighted average exercise price (in dollars per share) | $ / shares	$ 1.06
Expired (in shares) | shares	(500)
Expired, weighted average exercise price (in dollars per share) | $ / shares	$ 30.80
Outstanding at end of period (in shares) | shares	549,970
Outstanding at end of period, weighted average exercise price (in dollars per share) | $ / shares	$ 8.81
Outstanding, weighted average remaining contractual life (Year)	8 years
Outstanding, aggregate intrinsic value | $	$ 209,280
Exercisable at end of period (in shares) | shares	119,870
Exercisable at end of period, weighted average exercise price (in dollars per share) | $ / shares	$ 24.54
Exercisable, weighted average remaining contractual life (Year)	5 years 36 days
Exercisable, aggregate intrinsic value | $

Note 4 - Stock-based Compensa_5

Note 4 - Stock-based Compensation - Summary of Unvested Restricted Stock (Details) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Unvested at beginning of period (in shares)	15,000
Unvested at beginning of period, weighted average grant-date fair value (in dollars per share)	$ 2.75
Granted (in shares)	60,000
Granted, weighted average grant-date fair value (in dollars per share)	$ 2.90
Vested (in shares)	(15,000)	(5,000)
Vested, weighted average grant-date fair value (in dollars per share)	$ 2.75
Unvested at end of period (in shares)	60,000	15,000
Unvested at end of period, weighted average grant-date fair value (in dollars per share)	$ 2.90	$ 2.75

Note 5 - Loss Per Share (Detail

Note 5 - Loss Per Share (Details Textual) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Stock Options and Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	1,111,744	1,487,681
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares)	60,000	15,000

Note 6 - Stock Subscriptions _3

Note 6 - Stock Subscriptions and Other Receivables and Concentrations of Credit Risk (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable, Allowance for Credit Loss, Current	$ 0	$ 0
Customer Concentration Risk [Member] | Accounts and Other Receivables [Member] | An Investor [Member]
Concentration Risk, Percentage	98.00%	90.00%

Note 6 - Stock Subscriptions _4

Note 6 - Stock Subscriptions and Other Receivables and Concentrations of Credit Risk - Accounts and Other Receivables (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Accounts and other receivables	$ 2,987,319	$ 901,339
Stock Subscriptions [Member]
Accounts and other receivables	2,925,000	811,946
License Revenue Receivable [Member]
Accounts and other receivables	58,754
Grant Revenue Receivable [Member]
Accounts and other receivables	1,117	84,366
Other Accounts Receivable [Member]
Accounts and other receivables	$ 2,448	$ 5,027

Note 7 - Inventory (Details Tex

Note 7 - Inventory (Details Textual)	Dec. 31, 2020USD ($)
Inventory, Raw Materials, Gross, Total	$ 77,750
Inventory, Finished Goods, Gross, Total	92,048
Process Development [Member]
Inventory, Raw Materials, Gross, Total	11,000
Clinical Trials [Member]
Inventory, Finished Goods, Gross, Total	$ 39,000

Note 7 - Inventory - Net Invent

Note 7 - Inventory - Net Inventory (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Materials	$ 77,750
Finished goods	92,048
Inventory, Net, Total	$ 169,798

Note 8 - Property and Equipme_3

Note 8 - Property and Equipment (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Depreciation, Depletion and Amortization, Total	$ 33,929	$ 103,165

Note 8 - Property and Equipme_4

Note 8 - Property and Equipment - Summary of Major Classes of Property and Equipment (Details) - USD ($)		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Property and Equipment, Gross		$ 845,379	$ 1,207,537
Purchased Software [Member]
Property and Equipment, Useful Life (Year)		3 years
Property and Equipment, Gross		$ 320,435	320,435
Machinery and Equipment [Member]
Property and Equipment, Useful Life (Year)		5 years
Property and Equipment, Gross		$ 214,356	575,091
Other Machinery and Equipment [Member]
Property and Equipment, Gross		$ 297,315	296,987
Other Machinery and Equipment [Member] | Minimum [Member]
Property and Equipment, Useful Life (Year)		3 years
Other Machinery and Equipment [Member] | Maximum [Member]
Property and Equipment, Useful Life (Year)		5 years
Leasehold Improvements [Member]
Property and Equipment, Gross	[1]	$ 12,448	12,448
Property and Equipment, Useful Life	[1]	Term of Lease
Furniture and Fixtures [Member]
Property and Equipment, Useful Life (Year)		7 years
Property and Equipment, Gross		$ 825	$ 2,576
[1]	We amortize leasehold improvements over the term of the lease, which in all cases is shorter than the estimated useful life of the asset.

Note 9 - Investment in Macrop_2

Note 9 - Investment in Macrophage Therapeutics, Inc. (Details Textual) - USD ($)	Mar. 11, 2015	Nov. 30, 2018	Jul. 31, 2016	Mar. 31, 2015	May 31, 2016	Dec. 31, 2017	Dec. 31, 2015	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019	Aug. 31, 2018
Preferred Stock, Shares Authorized (in shares)								5,000,000		5,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share)								$ 0.001		$ 0.001
Preferred Stock, Shares Issued, Total (in shares)								0		0
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)								992,000
Derivative Liability, Total	$ 63,000									$ 0
Preferred Convertible Stock, Right to Exchange for Common Shares, Minimum Required Proceeds from Initial Public Offering							$ 50,000,000
Weighted Average Price Common Stock Percentage							80.00%
Future Common Stock Conversion Share Price (in dollars per share)							$ 60
Reclassification of Funds Invested						$ 200,000
Former Chief Executive Officer and President [Member]
Common Stock Shares Provided by Agreement (in shares)											1,175,000
Dr. Michael Goldberg [Member]
Convertible Preferred Stock, Percent of Shares Reserved				40.00%
Dr. Michael Goldberg [Member] | MT [Member]
Payments to Acquire Businesses and Interest in Affiliates, Total			$ 200,000
Resignation Agreement, Subidiary Percentage Ownership After Signing											5.00%
Resignation Agreement, Shares Issued (in shares)		925,000
Resignation Agreement, Shares in Escrow (in shares)		250,000
Macrophage Therapeutics [Member]
Common Stock Shares Authorized Upon Exercise of Warrants (in shares)				1,500
Convertible Preferred Stock Shares Issued Upon Conversion, Per Unit (in shares)				1
Common Stock Warrants, Issued Upon Conversion, Per Unit (in shares)				30
Macrophage Therapeutics [Member] | Common Stock [Member]
Common Stock as Percentage of Common Equity				1.00%
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	300								300
Platinum [Member] | MT [Member]
Payments to Acquire Businesses and Interest in Affiliates, Total			$ 300,000		$ 200,000
MT [Member]
Convertible Preferred Stock, PIK Coupon, Percentage			10.00%
Convertible Preferred Stock, Conversion Price, Market Cap			$ 500,000,000
Convertible Preferred Stock [Member]
Preferred Stock, Shares Authorized (in shares)				50
Preferred Stock, Par or Stated Value Per Share (in dollars per share)				$ 50,000
Cumulative Preferred Stock [Member]
Proceeds from Issuance of Preferred Stock, Preference Stock, and Warrants, Total	$ 500,000
Issuance of Stock and Warrants for Purchase Agreement, Remaining Amount							$ 2,000,000
Preferred Stock, Fair Value Put Option							113,000
Future Common Stock Conversion Denominator, Value							$ 50,000
Cumulative Preferred Stock [Member] | Macrophage Therapeutics [Member]
Preferred Stock, Shares Authorized (in shares)				50
Preferred Stock, Shares Issued, Total (in shares)				10
Preferred Stock, Redemption Price Per Share (in dollars per share)							$ 58,320

Note 10 - Accounts Payable, A_3

Note 10 - Accounts Payable, Accrued Liabilities and Other (Details Textual) - Director Fees [Member] - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Accounts Payable [Member]
Due to Related Parties, Current, Total	$ 66,000	$ 65,000
Accrued Liabilities and Other [Member]
Due to Related Parties, Current, Total	$ 755,000	$ 925,000

Note 10 - Accounts Payable, A_4

Note 10 - Accounts Payable, Accrued Liabilities and Other - Accrued Liabilities and Other (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Contracted services	$ 1,725,866	$ 1,212,347
Compensation	755,494	925,009
Other	31,634	13,618
Total accrued liabilities and other	$ 2,512,994	$ 2,150,974

Note 11 - Notes Payable (Detail

Note 11 - Notes Payable (Details Textual) - USD ($)	Feb. 23, 2021	May 18, 2020	Nov. 30, 2020	Nov. 30, 2019	Nov. 30, 2018	Dec. 31, 2020	Dec. 31, 2019
Interest Expense, Debt, Total						$ 6,000	$ 8,000
Notes Payable, Current, Total						745,443	305,955
Proceeds from Notes Payable, Total						366,000
Long-Term Debt, Maturity, Year One						379,000
Notes Payable Issued for Prepayment of Insurance Premiums [Member] | IPFS [Member]
Debt Instrument, Face Amount			$ 442,000	$ 349,000	$ 393,000
Debt Instrument, Interest Rate, Stated Percentage			3.50%	5.00%	5.10%
Debt Instrument, Term (Month)					300 days
Debt Instrument, Periodic Payment, Total			$ 64,000		$ 40,000
Interest Expense, Debt, Total						1,000	6,000
Notes Payable, Current, Total						379,000
Notes Payable Issued for Prepayment of Insurance Premiums [Member] | FIF [Member]
Debt Instrument, Face Amount				$ 349,000
Debt Instrument, Interest Rate, Stated Percentage				5.00%
Debt Instrument, Term (Month)				240 days
Debt Instrument, Periodic Payment, Total				$ 44,000
Interest Expense, Debt, Total						$ 5,000	1,000
Notes Payable, Current, Total							$ 306,000
Paycheck Protection Program CARES Act [Member]
Proceeds from Notes Payable, Total		$ 366,000
Paycheck Protection Program CARES Act [Member] | Subsequent Event [Member]
Forgiveness of Notes Payable	$ 366,000

Note 12 - Leases (Details Textu

Note 12 - Leases (Details Textual)	1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2017USD ($)	Mar. 31, 2019USD ($)ft²	Dec. 31, 2020USD ($)ft²	Dec. 31, 2019USD ($)	Jan. 01, 2019USD ($)
Operating Lease, Right-of-Use Asset			$ 250,095	$ 281,688	$ 406,842
Operating Lease, Expense			198,000	229,000
Operating Lease, Payments			$ 339,000	$ 330,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset					$ 407,000
Office Space at 4995 Bradenton Avenue, Dublin Ohio [Member]
Area of Real Estate Property (Square Foot) | ft²			5,000
Operating Lease, Monthly Base Rent			$ 3,000
Office Space at 560 Sylvan Avenue, Englewood Cliffs, New Jersey [Member]
Area of Real Estate Property (Square Foot) | ft²		2,000
Operating Lease, Monthly Base Rent		$ 3,000
Office Space at 5600 Blazer Parkway, Dublin, Ohio [Member]
Area of Real Estate Property (Square Foot) | ft²			25,000
Operating Lease, Monthly Base Rent			$ 27,000
Lessee, Operating Lease, Renewal Term (Year)			5 years
Operating Lease, Sublease, Monthly Rent Revenue	$ 39,000
Vehicle Lease [Member]
Operating Lease, Monthly Base Rent			$ 300
Office Equipment [Member]
Operating Lease, Monthly Base Rent			$ 100

Note 12 - Leases - Impact of th

Note 12 - Leases - Impact of the Adoption of ASU 2016-02 on Our Balance Sheet (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Operating Lease Right-of-use Assets, Pre-adoption balance	$ 250,095	$ 281,688	$ 406,842
Operating Lease Liabilities, Pre-adoption balance	$ 590,957		998,602
Terminated Lease Liability, Pre-adoption balance
Deferred Rent, Pre-adoption balance
Previous Accounting Guidance [Member]
Operating Lease Right-of-use Assets, Pre-adoption balance
Operating Lease Liabilities, Pre-adoption balance
Terminated Lease Liability, Pre-adoption balance			589,173
Deferred Rent, Pre-adoption balance			2,587
Adjustments for New Accounting Pronouncement [Member]
Operating Lease Right-of-use Assets, Pre-adoption balance			406,842
Operating Lease Liabilities, Pre-adoption balance			998,602
Terminated Lease Liability, Pre-adoption balance			(589,173)
Deferred Rent, Pre-adoption balance			$ (2,587)

Note 12 - Leases - Maturity of

Note 12 - Leases - Maturity of Lease Liabilities (Details) - USD ($)	Dec. 31, 2020	Jan. 01, 2019
2021	$ 344,552
2022	291,111
2023	19,699
2024	1,355
Total undiscounted operating lease payments	656,717
Less imputed interest	65,760
Present value of operating lease liabilities	$ 590,957	$ 998,602

Note 12 - Leases - Balance Shee

Note 12 - Leases - Balance Sheet Classification (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Current lease liabilities	$ 294,951	$ 250,553
Noncurrent lease liabilities	296,006	$ 512,344
Present value of operating lease liabilities	590,957		$ 998,602
Other Current Liabilities [Member]
Current lease liabilities	294,951
Other Noncurrent Liabilities [Member]
Noncurrent lease liabilities	$ 296,006

Note 12 - Leases - Other Inform

Note 12 - Leases - Other Information (Details)	Dec. 31, 2020
Weighted-average remaining lease term for operating leases (years) (Year)	1 year 328 days
Weighted-average discount rate for operating leases	10.90%

Note 13 - Commitments and Con_2

Note 13 - Commitments and Contingencies (Details Textual)

Mar. 16, 2021USD ($)

Nov. 27, 2019USD ($)

Apr. 26, 2019

Aug. 14, 2018

Apr. 09, 2018USD ($)

Nov. 02, 2017USD ($)

Mar. 03, 2017USD ($)

Nov. 30, 2018shares

Nov. 30, 2017USD ($)

Jun. 30, 2016USD ($)

Jan. 31, 2020shares

Dec. 31, 2020USD ($)shares

Dec. 31, 2019USD ($)shares

Feb. 14, 2020USD ($)

Aug. 31, 2018shares

Stock Issued During Period, Shares, New Issues (in shares) | shares

2,100,000

Stockholders' Equity Attributable to Parent, Ending Balance

$ 1,315,604

$ (1,612,292)

Market Capitalization, Fair Value

$ 58,400,000

Pro Forma [Member]

Stockholders' Equity Attributable to Parent, Ending Balance

$ 6,000,000

Common Stock [Member]

Stock Issued During Period, Shares, New Issues (in shares) | shares

1,647,059

8,000,000

Former Chief Executive Officer and President [Member]

Common Stock Shares Provided by Agreement (in shares) | shares

1,175,000

Common Stock Shares Provided by Agreement, Escrow Period (Month)

1 year 180 days

Former Chief Executive Officer and President [Member] | Common Stock [Member]

Stock Issued During Period, Shares, New Issues (in shares) | shares

925,000

Stock Issued During Period, Shares, New Issues Placed in Escrow (in shares) | shares

250,000

250,000

Former Chief Executive Officer and President [Member] | MT [Member] | Common Stock [Member] | Dr. Michael Goldberg [Member]

Ownership Percentage

5.00%

CRG [Member]

Draws on Letter of Credit

$ 7,100,000

CRG Loan Agreement, Texas Case [Member] | Judicial Ruling [Member]

Loss Contingency, Damages Awarded, Value, Additional Amount

$ 7,000,000

Loss Contingency, Damages Awarded, Value, Amount not Taken into Consideration

$ 4,100,000

Ohio Court of Common Pleas [Member]

Litigation Settlement, Amount Awarded from Other Party

$ 4,300,000

Ohio Court of Common Pleas [Member] | Subsequent Event [Member]

Litigation Settlement, Reversal of Amount Awarded from Other Party

$ 4,300,000

Platinum-Montaur Life Sciences LLC Litigation [Member]

Loss Contingency, Damages Sought, Value

$ 1,900,000

Platinum-Montaur Life Sciences LLC Litigation [Member] | Pending Litigation [Member]

Loss Contingency, Damages Sought, Value

$ 1,900,000

Maximum [Member] | Before Reverse Stock Split [Member]

Stockholders' Equity Note, Stock Split, Conversion Ratio

20

CRG [Member] | Term Loan Agreement [Member] | CRG Loan Agreement, Texas Case [Member] | Judicial Ruling [Member]

Repayments of Debt

59,000,000

CRG [Member] | Term Loan Agreement [Member] | Maximum [Member]

Debt Instrument, Agreed-upon Final Payoff Amount

$ 66,000,000

Note 14 - Equity Instruments (D

Note 14 - Equity Instruments (Details Textual) - USD ($)		Aug. 31, 2020	Aug. 30, 2020	Aug. 09, 2020	May 06, 2020	Mar. 22, 2019	May 31, 2020	Feb. 29, 2020	Jan. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Nov. 30, 2018	Jan. 31, 2020	Mar. 25, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Mar. 11, 2015
Stock Issued During Period, Value, New Issues																	$ 1,250,000	$ 5,166,441
Stock Issued During Period, Shares, New Issues (in shares)													2,100,000
Proceeds from Issuance of Common Stock									$ 812,000	$ 1,100,000			$ 1,900,000				4,442,560	7,086,915
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable															$ 4,975,000		4,975,000
Proceeds from Issuance of Preferred Stock and Preference Stock																	5,975,000
Preferred Stock, Shares Subscribed but Unissued, Subscriptions Receivable															$ 10,300,000		10,300,000
Stock Issued During Period, Value, Issued for Services																	$ 70,201	$ 14,800
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)																	32,651	8,128
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution																	$ 39,834	$ 19,588
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)															992,000		992,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	[1]														$ 18.37		$ 18.37
Common Stock, Capital Shares Reserved for Future Issuance (in shares)															1,541,844		1,541,844
Series OO Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)															$ 0.9375		$ 0.9375
Class of Warrant or Right, Exercised During Period (in shares)							411,000										411,000
Issued Stock Upon Exercise of Warrants, Shares (in shares)							300,595										300,595
Common Stock [Member]
Stock Issued During Period, Value, New Issues																	$ 1,647	$ 8,000
Stock Issued During Period, Shares, New Issues (in shares)																	1,647,059	8,000,000
Stock Issued During Period, Shares, Issued for Services (in shares)																	23,810	20,000
Stock Issued During Period, Value, Issued for Services																	$ 24	$ 20
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)																	94,159
Issued Stock Upon Exercise of Warrants, Shares (in shares)																	300,595
Common Stock [Member] | Former Chief Executive Officer and President [Member]
Stock Issued During Period, Shares, New Issues (in shares)												925,000
Stock Issued During Period, Shares, New Issues Placed in Escrow (in shares)												250,000					250,000
Common Stock [Member] | Macrophage Therapeutics [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)																			300		300
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)																			$ 2,000
Conversion from Series C Preferred Stock To Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)																	420,000
Conversion of Stock, Shares Issued (in shares)																	1,425,076
Conversion from Series D Preferred Stock To Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)																	17,750
Conversion of Stock, Shares Issued (in shares)																	827,280
Common Stock, Capital Shares Reserved for Future Issuance (in shares)															4,319,720		4,319,720
Conversion from Series D Preferred Stock To Common Stock [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares)														29,250
Conversion of Stock, Shares Converted (in shares)														29,250
Conversion of Stock, Shares Issued (in shares)														1,375,089
Series C Preferred Stock [Member]
Stock Issued During Period, Value, New Issues																	$ 4,163,178
Preferred Stock, Deemed Dividend																	$ 467,000
Conversion of Stock, Shares Converted (in shares)																	420,000
Series C Preferred Stock [Member] | Common Stock [Member]
Stock Issued During Period, Value, New Issues
Stock Issued During Period, Shares, New Issues (in shares)
Series D Preferred Stock [Member]
Stock Issued During Period, Value, New Issues																	$ 132,107
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable															$ 2,900,000		2,900,000
Preferred Stock, Deemed Dividend																	$ 197,000
Conversion of Stock, Shares Converted (in shares)																	17,750
Stock Subscriptions Receivable															2,900,000		$ 2,900,000
Preferred Stock, Shares Subscribed but Unissued, Subscriptions Receivable															10,300,000		10,300,000
Series D Preferred Stock [Member] | Common Stock [Member]
Stock Issued During Period, Value, New Issues
Stock Issued During Period, Shares, New Issues (in shares)
Investor [Member]
Stock Issued During Period, Shares, New Issues (in shares)								4,000,000									4,020,588
Proceeds from Issuance of Common Stock								$ 3,400,000								$ 3,400,000
Employees [Member] | Common Stock [Member]
Stock Issued During Period, Shares, Issued for Services (in shares)																	94,159	0
Stock Issued During Period, Value, Issued for Services																	$ 172,000
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)																	94,159
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution																	$ 172,000
Prepaid Expenses and Other Current Assets [Member]
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable										$ 812,000								$ 812,000
Keystone Capital Partners, LLC [Member] | Series C Preferred Stock [Member]
Stock Issued During Period, Value, New Issues					$ 4,200,000			$ 4,200,000
Stock Issued During Period, Shares, New Issues (in shares)					420,000			420,000									420,000
Proceeds from Issuance of Common Stock																	$ 4.20
Convertible Preferred Stock, Discount to Market Rate								10.00%
Convertible Preferred Stock, Maximum Allowed Percentage of Common Stock Outstanding Used in Conversion Shares								19.99%
Proceeds from Issuance of Preferred Stock and Preference Stock															$ 4,200,000
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Value, New Issues		$ 15,000,000
Stock Issued During Period, Shares, New Issues (in shares)		150,000															17,750
Convertible Preferred Stock, Discount to Market Rate		10.00%
Convertible Preferred Stock, Maximum Allowed Percentage of Common Stock Outstanding Used in Conversion Shares		19.99%
Preferred Stock, Deemed Dividend																	$ 197,000
Stock Issued During Period, Value, Other		$ 15
Proceeds from Issuance of Preferred Stock and Preference Stock																	$ 1,800,000
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares)														29,250
Proceeds from Issuance of Common Stock														$ 4,700,000
Proceeds from Issuance of Preferred Stock and Preference Stock														2,900,000
Jubilant [Member]
Stock Issued During Period, Shares, New Issues (in shares)				209,205
Proceeds from Issuance of Common Stock				$ 1,000,000
Maximum [Member]
Warrants and Rights Outstanding, Term (Year)															14 years 219 days		14 years 219 days
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)															$ 49.80		$ 49.80
Minimum [Member]
Warrants and Rights Outstanding, Term (Year)															73 days		73 days
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)															$ 0.20		$ 0.20
Weighted Average [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)															$ 18.37		$ 18.37
Private Placement [Member]
Stock Issued During Period, Value, New Issues						$ 50,000											$ 2,059	1,090,000
Shares Issued, Price Per Share (in dollars per share)						$ 2.80
Private Placement [Member] | Common Stock [Member]
Stock Issued During Period, Value, New Issues																	$ 3,281	$ 1,513
Stock Issued During Period, Shares, New Issues (in shares)																	3,280,691	1,173,411
Private Placement [Member] | Investor [Member]
Stock Issued During Period, Shares, New Issues (in shares)																	5,000
Sale of Stock, Commitment Amount			$ 25,000
Private Placement [Member] | Jubilant [Member]
Sale of Stock, Commitment Amount				$ 1,000,000
Private Placement [Member] | Mastiff Group LLC [Member]
Shares Issued, Price Per Share (in dollars per share)			$ 5
Stock Issued During Period, Shares, New Issues (in shares)			1,000,000
Sale of Stock, Commitment Amount			$ 25,000,000												$ 4,975,000		$ 4,975,000
Private Placement [Member] | Mastiff Group LLC [Member] | Subsequent Event [Member]
Proceeds from Issuance of Common Stock														$ 25,000
Private Placement [Member] | Maximum [Member]
Stock Purchase Agreement, Maximum Value																				$ 3,000,000
Private Placement [Member] | Maximum [Member] | Mastiff Group LLC [Member]
Shares Issued, Price Per Share (in dollars per share)			$ 5.75
Underwritten Public Offering [Member]
Shares Issued, Price Per Share (in dollars per share)											$ 0.75
Stock Issued During Period, Shares, New Issues (in shares)											8,000,000
Commission to Underwriter, Percentage of Gross Proceeds											7.50%
Stock Issued, Management Fee, Percentage											1.00%
Proceeds from Issuance of Common Stock											$ 5,555,000
Professional Fees											$ 127,000
Common Stock, Capital Shares Reserved for Future Issuance (in shares)															995,000		995,000
Underwritten Public Offering [Member] | Underwriter Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)											600,000
Common Stock Called By Warrants As Percentage Of Common Stock Sold											7.50%
Warrants and Rights Outstanding, Term (Year)											5 years
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)											$ 0.9375
Percent of Offering Price to Public Per Share											125.00%
Class of Warrant or Right, Grants in Period, Estimated Fair Value											$ 261,000
Underwritten Public Offering [Member] | Underwriter Warrants [Member] | Measurement Input, Price Volatility [Member]
Warrants and Rights Outstanding, Measurement Input											0.886
Underwritten Public Offering [Member] | Underwriter Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants and Rights Outstanding, Measurement Input											0.018
Underwritten Public Offering [Member] | Underwriter Warrants [Member] | Measurement Input, Expected Dividend Payment [Member]
Warrants and Rights Outstanding, Measurement Input											0
Underwritten Public Offering [Member] | Non-accountable Expenses [Member]
Payments of Stock Issuance Costs											$ 50,000
Underwritten Public Offering [Member] | Fees and Expenses of Legal Counsel [Member]
Payments of Stock Issuance Costs											100,000
Underwritten Public Offering [Member] | Clearing Expenses [Member]
Payments of Stock Issuance Costs											$ 10,000
Underwritten Public Offering [Member] | Offering Investor [Member]
Shares Issued, Price Per Share (in dollars per share)											$ 0.75
Stock Issued During Period, Shares, New Issues (in shares)											4,000,000
Underwritten Public Offering [Member] | Underwriter [Member]
Shares Issued, Price Per Share (in dollars per share)											$ 0.69375
Stock Issued During Period, Shares, New Issues (in shares)											4,000,000
Over-Allotment Option [Member] | Underwriter [Member]
Shares Issued, Price Per Share (in dollars per share)											$ 0.69375
Stock Issued During Period, Shares, New Issues (in shares)											1,200,000
[1]	Weighted average exercise price.

Note 14 - Equity Instruments -

Note 14 - Equity Instruments - Outstanding Warrants (Details)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Exercise Price (in dollars per share) | $ / shares	$ 18.37	[1]
Number of Warrants (in shares) | shares	991,874
Series HH Warrants [Member]
Exercise Price (in dollars per share) | $ / shares	$ 49.80
Number of Warrants (in shares) | shares	15,060
Expiration Date	Jun. 25, 2023
Series KK Warrants [Member]
Exercise Price (in dollars per share) | $ / shares	$ 38.36
Number of Warrants (in shares) | shares	19,550
Expiration Date	Mar. 4, 2021
Series LL Warrants [Member]
Exercise Price (in dollars per share) | $ / shares	$ 0.20
Number of Warrants (in shares) | shares	218,264
Expiration Date	Aug. 20, 2035
Series NN Warrants [Member]
Exercise Price (in dollars per share) | $ / shares	$ 30
Number of Warrants (in shares) | shares	550,000
Expiration Date	Mar. 3, 2022
Series OO Warrants [Member]
Exercise Price (in dollars per share) | $ / shares	$ 0.9375
Number of Warrants (in shares) | shares	189,000
Expiration Date	Jun. 13, 2024
[1]	Weighted average exercise price.

Note 15 - Income Taxes (Details

Note 15 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2020
Deferred Tax Assets, Gross, Total	$ 45,823,037	$ 43,612,033
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%
Revaluation of Deferred Tax Asset, Decrease			$ 26,400,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount			$ 26,400,000
Tax Credit Carryforwards, Alternative Minimum Tax, Percentage Included in Prepaid and Other Current Assets		50.00%
Tax Credit Carryforwards, Alternative Minimum Tax, Percentage Included in Other Noncurrent Assets		50.00%
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards, Total	$ 153,345,670	$ 142,200,000
Operating Loss Carryforwards Stock-based Compensation	15,000,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	20,100,000	20,100,000
Alternative Minimum Tax [Member]
Tax Credit Carryforward, Amount		621,000
Alternative Minimum Tax [Member] | Prepaid Expenses and Other Current Assets [Member]
Tax Credit Carryforward, Amount	0			$ 621,000
Research Tax Credit Carryforward [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Tax Credit Carryforward, Amount	8,912,821	8,800,000
Tax Credit Carryforward, Amount Expired During Period	$ 72,000	$ 130,000

Note 15 - Income Taxes - Compon

Note 15 - Income Taxes - Components of Deferred Tax Assets (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 34,365,098	$ 31,966,658
R&D credit carryforwards	9,301,709	9,150,580
AMT credit carryforward		310,620
Stock compensation	419,654	382,016
Intangibles	616,926	610,783
Disallowed interest expense	852,338	857,648
Temporary differences	267,312	333,728
Deferred tax assets before valuation allowance	45,823,037	43,612,033
Valuation allowance	(45,823,037)	(43,301,413)
Net deferred tax assets		$ 310,620

Note 15 - Income Taxes - Net Op

Note 15 - Income Taxes - Net Operating Loss and Credit Carryforwards (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards	$ 153,345,670	$ 142,200,000
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 8,912,821	$ 8,800,000
Tax Year 2001 [Member]
Expiration dates	Dec. 31, 2021
Tax Year 2001 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2001 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 39,128
Tax Year 2002 [Member]
Expiration dates	Dec. 31, 2022
Tax Year 2002 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2002 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 5,350
Tax Year 2003 [Member]
Expiration dates	Dec. 31, 2023
Tax Year 2003 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2003 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 2,905
Tax Year 2004 [Member]
Expiration dates	Dec. 31, 2024
Tax Year 2004 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2004 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 22,861
Tax Year 2005 [Member]
Expiration dates	Dec. 31, 2025
Tax Year 2005 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2005 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 218,332
Tax Year 2006 [Member]
Expiration dates	Dec. 31, 2026
Tax Year 2006 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2006 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 365,541
Tax Year 2007 [Member]
Expiration dates	Dec. 31, 2027
Tax Year 2007 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2007 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 342,898
Tax Year 2008 [Member]
Expiration dates	Dec. 31, 2028
Tax Year 2008 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2008 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 531,539
Tax Year 2009 [Member]
Expiration dates	Dec. 31, 2029
Tax Year 2009 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2009 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 596,843
Tax Year 2010 [Member]
Expiration dates	Dec. 31, 2030
Tax Year 2010 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2010 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 1,094,449
Tax Year 2011 [Member]
Expiration dates	Dec. 31, 2031
Tax Year 2011 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2011 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 1,950,744
Tax Year 2012 [Member]
Expiration dates	Dec. 31, 2032
Tax Year 2012 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards	$ 18,898,490
Tax Year 2012 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 468,008
Tax Year 2013 [Member]
Expiration dates	Dec. 31, 2033
Tax Year 2013 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards	$ 37,450,522
Tax Year 2013 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 681,772
Tax Year 2014 [Member]
Expiration dates	Dec. 31, 2034
Tax Year 2014 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards	$ 34,088,874
Tax Year 2014 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 816,116
Tax Year 2015 [Member]
Expiration dates	Dec. 31, 2035
Tax Year 2015 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards	$ 25,073,846
Tax Year 2015 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 492,732
Tax Year 2016 [Member]
Expiration dates	Dec. 31, 2036
Tax Year 2016 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards	$ 15,581,209
Tax Year 2016 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 262,257
Tax Year 2017 [Member]
Expiration dates	Dec. 31, 2037
Tax Year 2017 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2017 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 387,892
Tax Year 2018 [Member]
Expiration dates	Dec. 31, 2038
Tax Year 2018 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards
Tax Year 2018 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	197,547
Tax Year 2019 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards	11,245,808
Tax Year 2019 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	213,065
Tax Year 2020 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
U.S. Net Operating Loss Carryforwards	11,006,921
Tax Year 2020 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member] | Research Tax Credit Carryforward [Member]
U.S. R&D Credit Carryforwards	$ 222,842

Note 15 - Income Taxes - Reconc

Note 15 - Income Taxes - Reconciliations Between the Statutory Federal Income Tax Rate and the Effective Tax Rate (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Benefit at statutory rate, amount	$ (2,390,972)	$ (2,299,122)
Benefit at statutory rate, percent	(21.00%)	(21.00%)
Adjustments to valuation allowance, amount	$ 2,521,625	$ 2,355,947
Adjustments to valuation allowance, percent	22.10%	15.30%
Adjustments to R&D credit carryforwards, amount	$ (151,129)	$ (82,706)
Adjustments to R&D credit carryforwards, percent	(1.30%)	6.10%
Permanent items and other, amount	$ 20,476	$ 26,588
Permanent items and other, percent	0.20%	0.30%
Provision (benefit) per financial statements		$ 707

Note 16 - Segments (Details Tex

Note 16 - Segments (Details Textual)		12 Months Ended
		Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Revenues, Total		$ 915,013	$ 657,826
Number of Primary Types of Products Sold		2
Depreciation, Depletion and Amortization, Nonproduction, Total	[1]	$ 70,393	144,512
Selling, General and Administrative Expenses [Member]
Depreciation, Depletion and Amortization, Nonproduction, Total		70,393	$ 144,512
Intersegment Eliminations [Member]
Revenues, Total		$ 0
[1]	Depreciation and amortization are reflected in selling, general and administrative expenses ($70,393 and $144,512 for the years ended December 31, 2020 and 2019, respectively).

Note 16 - Segments - Segment In

Note 16 - Segments - Segment Information (Details) - USD ($)		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Revenue from contract with customer		$ 119,000	$ 38,000
Grant and other revenue		796,288	631,208
Revenues, Total		915,013	657,826
Cost of revenue		1,048	6,667
Research and Development Expense, Total		4,930,187	5,338,267
Selling, general and administrative expenses, excluding depreciation and amortization	[1]	6,624,566	6,130,897
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]	70,393	144,512
Loss from operations	[3]	(10,711,181)	(10,962,517)
Other expense	[4]	(10,510)	17,675
Net loss		(10,721,691)	(10,948,214)
Total assets, net of depreciation and amortization		7,758,018	4,150,906
Capital expenditures		135,881	1,258
Provision for income taxes			(707)
Loss from continuing operations			(10,945,549)
Loss from discontinued operations, net of tax effect			(2,665)
UNITED STATES
Total assets, net of depreciation and amortization		7,555,227	4,150,906
Non-US [Member]
Total assets, net of depreciation and amortization		202,791
Royalty [Member]
Revenue from contract with customer		7,995	16,665
License [Member]
Revenue from contract with customer		110,730	9,953
Diagnostics Segment [Member]
Grant and other revenue		482,221	384,776
Revenues, Total		600,946	411,394
Cost of revenue		1,048	6,667
Research and Development Expense, Total		4,593,459	4,795,445
Selling, general and administrative expenses, excluding depreciation and amortization	[1]	299,959
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]	10,068
Loss from operations	[3]	(4,303,588)	(4,390,718)
Other expense	[4]
Net loss		(4,303,588)	(4,393,666)
Capital expenditures		120,810
Provision for income taxes			(284)
Loss from continuing operations			(4,391,002)
Loss from discontinued operations, net of tax effect			(2,665)
Diagnostics Segment [Member] | UNITED STATES
Total assets, net of depreciation and amortization		139,121	55,229
Diagnostics Segment [Member] | Non-US [Member]
Total assets, net of depreciation and amortization		202,791
Diagnostics Segment [Member] | Royalty [Member]
Revenue from contract with customer		7,995	16,665
Diagnostics Segment [Member] | License [Member]
Revenue from contract with customer		110,730	9,953
Therapeutics Segment [Member]
Grant and other revenue		314,067	246,432
Revenues, Total		314,067	246,432
Cost of revenue
Research and Development Expense, Total		336,728	542,822
Selling, general and administrative expenses, excluding depreciation and amortization	[1]	800	16,990
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]
Loss from operations	[3]	(23,461)	(313,380)
Other expense	[4]
Net loss		(23,461)	(313,400)
Capital expenditures
Provision for income taxes			(20)
Loss from continuing operations			(313,400)
Loss from discontinued operations, net of tax effect
Therapeutics Segment [Member] | UNITED STATES
Total assets, net of depreciation and amortization			31,449
Therapeutics Segment [Member] | Non-US [Member]
Total assets, net of depreciation and amortization
Therapeutics Segment [Member] | Royalty [Member]
Revenue from contract with customer
Therapeutics Segment [Member] | License [Member]
Revenue from contract with customer
Corporate Segment [Member]
Grant and other revenue
Revenues, Total
Cost of revenue
Research and Development Expense, Total
Selling, general and administrative expenses, excluding depreciation and amortization	[1]	6,323,807	6,113,907
Depreciation, Depletion and Amortization, Nonproduction, Total	[2]	60,325	144,512
Loss from operations	[3]	(6,384,132)	(6,258,419)
Other expense	[4]	(10,510)	17,675
Net loss		(6,394,642)	(6,241,147)
Capital expenditures		15,071	1,258
Provision for income taxes			(403)
Loss from continuing operations			(6,241,147)
Loss from discontinued operations, net of tax effect
Corporate Segment [Member] | UNITED STATES
Total assets, net of depreciation and amortization		7,416,106	4,064,228
Corporate Segment [Member] | Non-US [Member]
Total assets, net of depreciation and amortization
Corporate Segment [Member] | Royalty [Member]
Revenue from contract with customer
Corporate Segment [Member] | License [Member]
Revenue from contract with customer
[1]	General and administrative expenses, excluding depreciation and amortization, represent costs that relate to the general administration of the Company and as such are not currently allocated to our individual reportable segments, other than those expenses directly incurred by Navidea Europe, Navidea UK and MT.
[2]	Depreciation and amortization are reflected in selling, general and administrative expenses ($70,393 and $144,512 for the years ended December 31, 2020 and 2019, respectively).
[3]	Loss from operations does not reflect the allocation of certain selling, general and administrative expenses, excluding depreciation and amortization, to our individual reportable segments, other than those expenses directly incurred by Navidea Europe, Navidea UK and MT.
[4]	Amounts consist primarily of interest income and interest expense, which are not currently allocated to our individual reportable segments.

Note 17 - Material Agreements (

Note 17 - Material Agreements (Details Textual) - USD ($)	1 Months Ended			12 Months Ended
	Jul. 31, 2014	Nov. 30, 2009	Jan. 31, 2002	Dec. 31, 2020	Dec. 31, 2019
Research and Development Expense, Total				$ 4,930,187	$ 5,338,267
Reliable Supply Agreement [Member]
Long-term Contract for Supplies, Option to Extend, Term (Year)		3 years
Tc99m Tilmanocept License Agreement [Member]
License Issue Fee			$ 25,000
License Maintenance Fee			25,000
Minimum Annual Royalty			$ 25,000
Expanded Tc99m Tilmanocept License Agreement [Member] | Outside the Territory [Member] | Cost of Sales [Member] | License [Member]
Cost of Goods and Services Sold, Total				1,000	2,000
Amended and Restated Tilmanocept License Agreement [Member]
Research and Development Expense, Total				34,000	191,000
Tilmanocept License Agreement [Member]
License Issue Fee	$ 25,000
License Maintenance Fee	25,000
Minimum Annual Royalty	$ 25,000
Research and Development Expense, Total				275,000	$ 355,000
Employment Agreement [Member] | Maximum [Member]
Loss Contingency, Estimate of Possible Loss				$ 2,500,000

Note 18 - Employee Benefit Pl_2

Note 18 - Employee Benefit Plan (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Contribution Plan, Cost	$ 49,000	$ 14,000

Note 19 - Supplemental Disclo_2

Note 19 - Supplemental Disclosure for Statements of Cash Flows (Details Textual) - USD ($)	1 Months Ended		12 Months Ended
	May 31, 2020	Feb. 29, 2020	Dec. 31, 2020	Dec. 31, 2019	Nov. 30, 2020	Nov. 30, 2019	Jan. 01, 2019	Nov. 30, 2018
Interest Paid, Excluding Capitalized Interest, Operating Activities			$ 6,000	$ 8,000
Operating Lease, Right-of-Use Asset			$ 250,095	$ 281,688			$ 406,842
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)			32,651	8,128
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution			$ 39,834	$ 19,588
Stock Issued During Period, Shares, Employee Benefit Plan (in shares)			32,651	8,128
Operating Lease, Liability, Total			$ 590,957				998,602
Conversion from Series C Preferred Stock To Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)			420,000
Conversion of Stock, Shares Issued (in shares)			1,425,076
Conversion from Series D Preferred Stock To Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)			17,750
Conversion of Stock, Shares Issued (in shares)			827,280
Series C Preferred Stock [Member]
Preferred Stock, Deemed Dividend			$ 467,000
Conversion of Stock, Shares Converted (in shares)			420,000
Series D Preferred Stock [Member]
Preferred Stock, Deemed Dividend			$ 197,000
Conversion of Stock, Shares Converted (in shares)			17,750
Series OO Warrants [Member]
Class of Warrant or Right, Exercised During Period (in shares)	411,000		411,000
Issued Stock Upon Exercise of Warrants, Shares (in shares)	300,595		300,595
Notes Payable Issued for Prepayment of Insurance Premiums [Member] | IPFS [Member]
Debt Instrument, Face Amount					$ 442,000	$ 349,000		$ 393,000
Debt Instrument, Interest Rate, Stated Percentage					3.50%	5.00%		5.10%
Common Stock [Member]
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)			94,159
Stock Issued During Period, Shares, Employee Benefit Plan (in shares)			32,651	8,128
Issued Stock Upon Exercise of Warrants, Shares (in shares)			300,595
Employees [Member] | Common Stock [Member]
Stock Issued During Period, Shares, Issued for Employee Bonuses (in shares)			94,159
Issuance of Stock to Defined Contribution Plan for Employer Matching Contribution			$ 172,000
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset							407,000
Operating Lease, Liability, Total							$ 407,000
Office Lease [Member]
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability		$ 100,432

Note 20 - Subsequent Events (De

Note 20 - Subsequent Events (Details Textual)	Mar. 02, 2021USD ($)shares	Aug. 31, 2020USD ($)shares	Jan. 31, 2020shares	Mar. 25, 2021USD ($)shares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)
Stock Issued During Period, Shares, New Issues (in shares) | shares			2,100,000
Stock Issued During Period, Value, New Issues					$ 1,250,000	$ 5,166,441
Proceeds from Issuance of Preferred Stock and Preference Stock					5,975,000
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable					4,975,000
Preferred Stock, Shares Subscribed but Unissued, Subscriptions Receivable					$ 10,300,000
Conversion from Series D Preferred Stock To Common Stock [Member]
Conversion of Stock, Shares Converted (in shares) | shares					17,750
Conversion of Stock, Shares Issued (in shares) | shares					827,280
Conversion from Series D Preferred Stock To Common Stock [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares				29,250
Conversion of Stock, Shares Converted (in shares) | shares				29,250
Conversion of Stock, Shares Issued (in shares) | shares				1,375,089
Series D Preferred Stock [Member]
Stock Issued During Period, Value, New Issues					$ 132,107
Conversion of Stock, Shares Converted (in shares) | shares					17,750
Common Stock, Share Subscribed but Unissued, Subscriptions Receivable					$ 2,900,000
Preferred Stock, Shares Subscribed but Unissued, Subscriptions Receivable					$ 10,300,000
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares		150,000			17,750
Stock Issued During Period, Value, New Issues		$ 15,000,000
Proceeds from Issuance of Preferred Stock and Preference Stock					$ 1,800,000
Keystone Capital Partners, LLC [Member] | Series D Preferred Stock [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares				29,250
Proceeds from Issuance of Preferred Stock and Preference Stock				$ 2,900,000
John K. Scott, Jr. [Member] | Series E Preferred Stock [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares	50,000
Stock Issued During Period, Value, New Issues	$ 5,000,000
Debt Instrument, Convertible, Number of Equity Instruments	2,173,913