XML 13 R1.htm IDEA: XBRL DOCUMENT v3.25.2
Cover Page - shares
 6 Months Ended
Jun. 30, 2025
Aug. 12, 2025
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 001-42668  
Entity Registrant Name Kestrel Group Ltd  
Entity Incorporation, State or Country Code D0  
Entity Tax Identification Number 98-1833921  
Entity Address, Address Line One 11 Bermudiana Road, Suite 1141  
Entity Address, City or Town Hamilton  
Entity Address, Country BM  
Entity Address, Postal Zip Code HM 08  
City Area Code 441  
Local Phone Number 298-4900  
Title of 12(b) Security Common Shares, par value $0.01 per share  
Trading Symbol KG  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   7,741,943
Amendment Flag false  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Entity Central Index Key 0002055116  
Current Fiscal Year End Data --12-31