Document And Entity Information - USD ($)	Dec. 31, 2021	Apr. 07, 2022	Jun. 30, 2021
Document Information [Line Items]
Entity, Registrant Name	THERMOGENESIS HOLDINGS, INC.
Document, Type	10-K/A
Document, Annual Report	true
Document, Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document, Fiscal Period Focus	FY
Document, Fiscal Year Focus	2021
Document, Transition Report	false
Entity, File Number	000-16375
Entity, Incorporation, State or Country Code	DE
Entity, Tax Identification Number	94-3018487
Entity, Address, Address Line One	2711 Citrus Road
Entity, Address, City or Town	Rancho Cordova
Entity, Address, State or Province	CA
Entity, Address, Postal Zip Code	95742
City Area Code	916
Local Phone Number	858-5100
Title of 12(b) Security	Common Stock
Trading Symbol	THMO
Security Exchange Name	NASDAQ
Entity, Well-known Seasoned Issuer	No
Entity, Voluntary Filers	No
Entity, Current Reporting Status	Yes
Entity, Interactive Data, Current	Yes
Entity, Filer Category	Non-accelerated Filer
Entity, Small Business	true
Entity, Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity, Shell Company	false
Entity, Public Float			$ 26,985,000
Entity, Common Stock Shares, Outstanding		12,829,877
Auditor Name	Marcum LLP
Auditor Location	New York, NY
Auditor Firm ID	688
Amendment Description	This Amendment No. 1 (this “Amendment”) amends the Annual Report on Form 10-K for the year ended December 31, 2021, of ThermoGenesis Holdings, Inc. (the “Company,” “we”, or “our”) which we filed with the Securities and Exchange Commission (the “SEC”) on March 28, 2022 (the “Original Filing”). This Amendment is being filed to amend and restate Items 10, 11, 12, 13, and 14 of Part III of the Form 10-K in their entirety to provide the information that the Company indicated that it would incorporate by reference from its Proxy Statement for the 2021 annual report of the stockholders in reliance on General Instruction G(3) to Form 10-K.   In addition, as required by Rule 12b-15 under the Securities Exchange Action of 1934, as amended (the “Exchange Act”), this Amendment revises Item 15 of Part IV to include currently dated certifications by the Company’s principal executive officer and principal financial officer as exhibits to this Amendment and updates the Exhibit Index to reflect the inclusion of these certifications.   Other than the items outlined above, this Amendment does not attempt to modify or update the Original Filing. This Amendment does not reflect events occurring after the date of the Original Filing or modify or update those disclosures that may be affected by subsequent events. Such subsequent matters are addressed in subsequent reports filed by the Company with the SEC. Accordingly, this Amendment should be read in conjunction with the Original Filing. Capitalized terms not defined in this Amendment have the meaning given to them in the Original Filing.
Amendment Flag	true
Entity, Central Index Key	0000811212