Condensed Financial Information of Registrant (Parent Only) Statement of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	$ 42,886	$ 44,236	$ 90,799
Cash flows from investing activities:
Proceeds from sale of fixed maturities	148,164	933,554	1,065,398
Proceeds from sale of equity securities	1,158	88,726	54,691
Proceeds from maturity of fixed maturities	280,115	81,546	87,057
Proceeds from other invested assets	2,309	107,925	17,082
Purchases of fixed maturities	(448,465)	(1,164,683)	(1,207,231)
Purchases of equity securities	(111)	(10,660)	(42,905)
Purchases of other invested assets	0	0	(70,000)
Net cash provided by (used for) investing activities	(16,330)	80,134	(64,519)
Cash flows from financing activities:
Distributions paid to common shareholders	(14,248)	(14,366)	(14,431)
Distributions paid to preferred shareholders	(440)	(440)	(440)
Purchases of class A common shares	(12,677)	(22,335)	(490)
Issuance of class A common shares	0	3,339	0
Net cash used for financing activities	(27,365)	(163,802)	(15,361)
Net change in cash and cash equivalents	(809)	(39,432)	10,919
Cash and cash equivalents at beginning of period	38,846	78,278	67,359
Cash and cash equivalents at end of period	38,037	38,846	78,278
Parent Company | Global Indemnity Group LLC
Condensed Financial Statements, Captions [Line Items]
Net cash provided by operating activities	4,388	7,720	7,264
Cash flows from investing activities:
Proceeds from sale of fixed maturities	17,226	70,151	84,070
Proceeds from sale of equity securities	1,158	76,466	27,600
Proceeds from maturity of fixed maturities	240	438	1,087
Proceeds from other invested assets	0	58,577	0
Purchases of fixed maturities	(271)	(105,025)	(60,800)
Purchases of equity securities	(111)	(939)	(30,956)
Purchases of other invested assets	0	0	(25,000)
Net cash provided by (used for) investing activities	18,242	99,668	(3,999)
Cash flows from financing activities:
Distributions paid to common shareholders	(14,248)	(14,366)	(14,431)
Distributions paid to preferred shareholders	(440)	(440)	(440)
Issuance of note receivable to affiliates	0	(69,400)	0
Proceeds from the repayment of a note receivable from affiliate	0	0	11,283
Proceeds from issuance of note payable to affiliates	0	0	2,800
Repayment of note payable to affiliates	0	(2,800)	0
Purchases of class A common shares	(12,677)	(22,335)	(490)
Issuance of class A common shares	0	3,339	0
Net cash used for financing activities	(27,365)	(106,002)	(1,278)
Net change in cash and cash equivalents	(4,735)	1,386	1,987
Cash and cash equivalents at beginning of period	4,775	3,389	1,402
Cash and cash equivalents at end of period	$ 40	$ 4,775	$ 3,389