Schedule of Condensed Consolidating Statements of Operations (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Net earned premiums		$ 141,847	$ 128,201	$ 286,315	$ 250,290
Net investment income (loss)		(2,359)	13,826	7,770	21,045
Net realized investment gains (losses)		38,507	3,590	(29,655)	13,980
Other income		766	522	931	1,010
Total revenues		178,761	146,139	265,361	286,325
Losses and Expenses:
Net losses and loss adjustment expenses		67,297	70,075	144,944	128,396
Acquisition costs and other underwriting expenses		53,578	50,534	109,990	100,277
Corporate and other operating expenses		8,618	4,639	12,841	7,844
Interest expense		4,712	5,042	9,577	10,065
Income (loss) before income taxes		44,556	15,849	(11,991)	39,743
Equity in net income (loss) of subsidiaries		0	0	0	0
Income (loss) before income taxes		44,556	15,849	(11,991)	39,743
Income tax expense (benefit)		7,005	1,186	(4,964)	5,480
Net income (loss)		37,551	14,663	(7,027)	34,263
Global Indemnity Limited (Parent co-obligor) | Reportable Legal Entities
Revenues:
Net earned premiums		0	0	0	0
Net investment income (loss)		800	729	598	1,371
Net realized investment gains (losses)		1,857	406	(2,746)	399
Other income		0	0	0	0
Total revenues		2,657	1,135	(2,148)	1,770
Losses and Expenses:
Net losses and loss adjustment expenses		0	0	0	0
Acquisition costs and other underwriting expenses		0	0	0	0
Corporate and other operating expenses		4,969	1,657	6,142	2,986
Interest expense		277	277	553	551
Income (loss) before income taxes		(2,589)	(799)	(8,843)	(1,767)
Equity in net income (loss) of subsidiaries		40,140	15,462	1,816	36,030
Income (loss) before income taxes		37,551	14,663	(7,027)	34,263
Income tax expense (benefit)		0	0	0	0
Net income (loss)		37,551	14,663	(7,027)	34,263
GBLI Holdings, LLC (Subsidiary co-obligor) | Reportable Legal Entities
Revenues:
Net earned premiums		0	0	0	0
Net investment income (loss)		(10,583)	5,020	(8,512)	2,945
Net realized investment gains (losses)		23,484	(582)	(40,707)	11,494
Other income		0	2	19	30
Total revenues		12,901	4,440	(49,200)	14,469
Losses and Expenses:
Net losses and loss adjustment expenses		0	0	0	0
Acquisition costs and other underwriting expenses		0	0	0	0
Corporate and other operating expenses		3,527	2,681	6,481	4,247
Interest expense		4,637	4,961	9,436	9,918
Income (loss) before income taxes		4,737	(3,202)	(65,117)	304
Equity in net income (loss) of subsidiaries		22,683	7,005	32,821	14,898
Income (loss) before income taxes		27,420	3,803	(32,296)	15,202
Income tax expense (benefit)		1,632	(1,503)	(12,431)	(163)
Net income (loss)		25,788	5,306	(19,865)	15,365
Other Global Indemnity Limited Subsidiaries and Eliminations (non-co-obligor subsidiaries)
Revenues:
Net earned premiums	[1]	141,847	128,201	286,315	250,290
Net investment income (loss)	[1]	7,690	8,366	16,227	17,305
Net realized investment gains (losses)	[1]	13,166	3,766	13,798	2,087
Other income	[1]	766	520	912	980
Total revenues	[1]	163,469	140,853	317,252	270,662
Losses and Expenses:
Net losses and loss adjustment expenses	[1]	67,297	70,075	144,944	128,396
Acquisition costs and other underwriting expenses	[1]	53,578	50,534	109,990	100,277
Corporate and other operating expenses	[1]	122	301	218	611
Interest expense	[1]	64	93	131	172
Income (loss) before income taxes	[1]	42,408	19,850	61,969	41,206
Equity in net income (loss) of subsidiaries	[1]	25,788	5,306	(19,865)	15,365
Income (loss) before income taxes	[1]	68,196	25,156	42,104	56,571
Income tax expense (benefit)	[1]	5,373	2,689	7,467	5,643
Net income (loss)	[1]	62,823	22,467	34,637	50,928
Consolidation Adjustments
Revenues:
Net earned premiums	[2]	0	0	0	0
Net investment income (loss)	[2]	(266)	(289)	(543)	(576)
Net realized investment gains (losses)	[2]	0	0	0	0
Other income	[2]	0	0	0	0
Total revenues	[2]	(266)	(289)	(543)	(576)
Losses and Expenses:
Net losses and loss adjustment expenses	[2]	0	0	0	0
Acquisition costs and other underwriting expenses	[2]	0	0	0	0
Corporate and other operating expenses	[2]	0	0	0	0
Interest expense	[2]	(266)	(289)	(543)	(576)
Income (loss) before income taxes	[2]	0	0	0	0
Equity in net income (loss) of subsidiaries	[2]	(88,611)	(27,773)	(14,772)	(66,293)
Income (loss) before income taxes	[2]	(88,611)	(27,773)	(14,772)	(66,293)
Income tax expense (benefit)	[2]	0	0	0	0
Net income (loss)	[2]	$ (88,611)	$ (27,773)	$ (14,772)	$ (66,293)

[1] Includes all other subsidiaries of Global Indemnity Limited and eliminations

[2] Includes Parent co-obligor and subsidiary co-obligor consolidating adjustments