Cover - USD ($)	12 Months Ended
Cover - USD ($)	Dec. 31, 2022	Mar. 13, 2023	Jun. 30, 2022
Cover [Abstract]
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-39392
Entity Registrant Name	TREAN INSURANCE GROUP, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-4512647
Entity Address, Address Line One	150 Lake Street West
Entity Address, City or Town	Wayzata
Entity Address, State or Province	MN
Entity Address, Postal Zip Code	55391
City Area Code	952
Local Phone Number	974-2200
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	TIG
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	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 139,680,681
Entity Common Stock, Shares Outstanding		51,238,218
Amendment Description	Trean Insurance Group, Inc. (also referred to herein as the “Company,” “we,” “us” or “our”) filed its Annual Report on Form 10-K for the fiscal year ended December 31, 2022 (the “Original Form 10-K”) with the United States Securities and Exchange Commission (the “Commission”) on March 16, 2023. The Company is filing this Amendment No. 1 to the Original Form 10-K (this “Form 10-K/A”, and together with the Original form 10-K, the “Report”) solely for the purpose of including in Part III the information that was to be incorporated by reference from the Company’s definitive proxy statement for its 2023 Annual Meeting of Stockholders because the Company’s definitive proxy statement will not be filed with the Commission within 120 days after the end of the Company’s fiscal year ended December 31, 2022. This Form 10-K/A hereby amends and restates in their entirety Items 10 through 14 of Part III of the Original Form 10-K. Additionally, this Form 10-K/A hereby amends and restates the cover page of the Original Form 10-K to remove the statement that information is being incorporated by reference from the Company’s definitive proxy statement.
Amendment Flag	true
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Entity Central Index Key	0001801754
Auditor Name	Deloitte & Touche LLP
Auditor Firm ID	34
Document Type	10-K/A
Auditor Location	Minneapolis, Minnesota

Trean Insurance Group, Inc. 10-K/A