Schedule of Condensed Consolidating Statements of Operations (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Net premiums earned		$ 133,312	$ 120,528	$ 383,602	$ 342,447
Net investment income		11,348	11,750	32,393	34,108
Net realized investment gains (losses)		(2,690)	5,319	11,290	7,833
Other income (loss)		264	411	1,274	1,289
Total revenues		142,234	138,008	428,559	385,677
Losses and Expenses:
Net losses and loss adjustment expenses		73,583	80,493	201,979	195,426
Acquisition costs and other underwriting expenses		53,366	48,680	153,643	141,196
Corporate and other operating expenses		3,858	3,475	11,702	23,653
Interest expense		5,023	4,924	15,088	14,725
Income before income taxes		6,404	436	46,147	10,677
Equity in net income (loss) of subsidiaries		0	0	0	0
Income (loss) before income taxes		6,404	436	46,147	10,677
Income tax expense (benefit)		(317)	(3,292)	5,163	(5,944)
Net income		6,721	3,728	40,984	16,621
Global Indemnity Limited (Parent co-obligor) | Reportable Legal Entities
Revenues:
Net premiums earned		0	0	0	0
Net investment income		393	146	1,764	483
Net realized investment gains (losses)		(101)	(101)	298	(121)
Other income (loss)		0	0	0	0
Total revenues		292	45	2,062	362
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		1,320	982	4,306	9,959
Interest expense		278	2,017	829	12,715
Income before income taxes		(1,306)	(2,954)	(3,073)	(22,312)
Equity in net income (loss) of subsidiaries		8,027	6,682	44,057	38,933
Income (loss) before income taxes		6,721	3,728	40,984	16,621
Income tax expense (benefit)		0	0	0	0
Net income		6,721	3,728	40,984	16,621
Global Indemnity Group, Inc.(Subsidiary co-obligor) | Reportable Legal Entities
Revenues:
Net premiums earned		0	0	0	0
Net investment income		2,798	2,492	5,743	8,404
Net realized investment gains (losses)		(3,525)	5,321	7,969	8,167
Other income (loss)		0	(12)	30	0
Total revenues		(727)	7,801	13,742	16,571
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		2,159	2,089	6,406	12,734
Interest expense		4,957	12,035	14,875	34,773
Income before income taxes		(7,843)	(6,323)	(7,539)	(30,936)
Equity in net income (loss) of subsidiaries		1,699	(3,995)	16,597	6,770
Income (loss) before income taxes		(6,144)	(10,318)	9,058	(24,166)
Income tax expense (benefit)		(1,682)	(1,884)	(1,845)	(2,831)
Net income		(4,462)	(8,434)	10,903	(21,335)
Other Global Indemnity Limited Subsidiaries and Eliminations (non-co-obligor subsidiaries)
Revenues:
Net premiums earned	[1]	133,312	120,528	383,602	342,447
Net investment income	[1]	8,442	18,318	25,747	58,258
Net realized investment gains (losses)	[1]	936	99	3,023	(213)
Other income (loss)	[1]	264	423	1,244	1,289
Total revenues	[1]	142,954	139,368	413,616	401,781
Losses and Expenses:
Net losses and loss adjustment expenses	[1]	73,583	80,493	201,979	195,426
Acquisition costs and other underwriting expenses	[1]	53,366	48,680	153,643	141,196
Corporate and other operating expenses	[1]	379	404	990	960
Interest expense	[1]	73	78	245	274
Income before income taxes	[1]	15,553	9,713	56,759	63,925
Equity in net income (loss) of subsidiaries	[1]	(4,462)	(8,434)	10,903	(21,335)
Income (loss) before income taxes	[1]	11,091	1,279	67,662	42,590
Income tax expense (benefit)	[1]	1,365	(1,408)	7,008	(3,226)
Net income	[1]	9,726	2,687	60,654	45,816
Consolidation Adjustments
Revenues:
Net premiums earned	[2]	0	0	0	0
Net investment income	[2]	(285)	(9,206)	(861)	(33,037)
Net realized investment gains (losses)	[2]	0	0	0	0
Other income (loss)	[2]	0	0	0	0
Total revenues	[2]	(285)	(9,206)	(861)	(33,037)
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]	(285)	(9,206)	(861)	(33,037)
Income before income taxes	[2]	0	0	0	0
Equity in net income (loss) of subsidiaries	[2]	(5,264)	5,747	(71,557)	(24,368)
Income (loss) before income taxes	[2]	(5,264)	5,747	(71,557)	(24,368)
Income tax expense (benefit)	[2]	0	0	0	113
Net income	[2]	$ (5,264)	$ 5,747	$ (71,557)	$ (24,481)

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

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