Related Party Transactions - Additional Information (Detail) - USD ($)		3 Months Ended		6 Months Ended
	Aug. 27, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Series A Preferred Interest
Related Party Transaction [Line Items]
Preferred interests, non-voting description				While these preferred interests are non-voting, the preferred shareholders are entitled to appoint two additional members to Global Indemnity Group, LLC’s Board of Directors whenever the “Unpaid Targeted Priority Return” with respect to the preferred interests exceed zero immediately following six or more “Distribution Dates”, whether or not such Distribution Dates occur consecutively
Fox Paine Entities
Related Party Transaction [Line Items]
Company's total voting power		82.90%		82.90%
Wyncote LLC | Series A Preferred Interest
Related Party Transaction [Line Items]
Preferred shares issued	4,000
Shares issued, price per share	$ 1,000
Preferred shares issued, value	$ 4,000,000
Fox Paine and Company
Related Party Transaction [Line Items]
Management fees		$ 700,000	$ 800,000	$ 1,300,000	$ 1,400,000
Prepaid management fees		$ 500,000		$ 500,000		$ 1,800,000