Schedule of Condensed Consolidating Balance Sheets (Detail) - USD ($) $ in Thousands		Sep. 30, 2020		Jun. 30, 2020	Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019	Dec. 31, 2018
ASSETS
Total investments		$ 1,417,465			$ 1,563,542
Cash and cash equivalents		37,211			44,271		$ 78,181			$ 99,497
Investments in subsidiaries		0			0
Due from subsidiaries and affiliates		0			0
Notes receivable – affiliate		0			0
Interest receivable – affiliate		0			0
Premiums receivable, net		109,820			118,035
Reinsurance receivables, net		112,633			83,938
Funds held by ceding insurers		46,894			48,580
Federal income taxes receivable		0			10,989
Deferred federal income taxes		35,300			31,077
Deferred acquisition costs		67,470			70,677
Intangible assets		21,094			21,491
Goodwill		6,521			6,521
Prepaid reinsurance premiums		15,558			16,716
Other assets		69,791			60,048
Total assets		1,939,757			2,075,885		2,084,156
Liabilities:
Unpaid losses and loss adjustment expenses		669,930		$ 651,073	630,181		633,287		$ 608,773	680,031
Unearned premiums		304,074			314,861
Ceded balances payable		9,576			20,404
Payable for securities purchased		5,630			850
Contingent commissions		11,329			11,928
Debt		126,253			296,640
Notes payable – affiliates		0			0
Accrued interest payable – affiliates		0			0
Other liabilities		92,252			74,212
Total liabilities		1,219,044			1,349,076
Shareholders’ equity
Total shareholders’ equity		720,713			726,809		707,384
Total liabilities and shareholders’ equity		1,939,757			2,075,885
Global Indemnity Group, LLC (Parent co-obligor) | Reportable Legal Entities
ASSETS
Total investments		212,050			44,468
Cash and cash equivalents		13,765	[1]		977	[1]	3,604			2,221
Investments in subsidiaries		491,851			1,218,491
Due from subsidiaries and affiliates		(3,999)			(3,612)
Notes receivable – affiliate		11,283			0
Interest receivable – affiliate		16			0
Premiums receivable, net		0			0
Reinsurance receivables, net		0			0
Funds held by ceding insurers		0			0
Federal income taxes receivable		0			0
Deferred federal income taxes		0			0
Deferred acquisition costs		0			0
Intangible assets		0			0
Goodwill		0			0
Prepaid reinsurance premiums		0			0
Other assets		13,240			9,394
Total assets		738,206			1,269,718
Liabilities:
Unpaid losses and loss adjustment expenses		0			0
Unearned premiums		0			0
Ceded balances payable		0			0
Payable for securities purchased		2,207			0
Contingent commissions		0			0
Debt		0			0
Notes payable – affiliates		0			520,498
Accrued interest payable – affiliates		0			20,343
Other liabilities		15,286			2,068
Total liabilities		17,493			542,909
Shareholders’ equity
Total shareholders’ equity		720,713			726,809
Total liabilities and shareholders’ equity		738,206			1,269,718
GBLI Holdings, LLC (Subsidiary co-obligor) | Reportable Legal Entities
ASSETS
Total investments		48,940			257,317
Cash and cash equivalents		2,575			2,663		22,966			26,039
Investments in subsidiaries		387,913			355,777
Due from subsidiaries and affiliates		(7,522)			(3,965)
Notes receivable – affiliate		0			80,049
Interest receivable – affiliate		0			5,014
Premiums receivable, net		0			0
Reinsurance receivables, net		0			0
Funds held by ceding insurers		0			0
Federal income taxes receivable		2,892			14,197
Deferred federal income taxes		38,805			31,833
Deferred acquisition costs		0			0
Intangible assets		0			0
Goodwill		0			0
Prepaid reinsurance premiums		0			0
Other assets		19,444			12,622
Total assets		493,047			755,507
Liabilities:
Unpaid losses and loss adjustment expenses		0			0
Unearned premiums		0			0
Ceded balances payable		0			0
Payable for securities purchased		0			0
Contingent commissions		0			0
Debt		130,000			303,629
Notes payable – affiliates		0			0
Accrued interest payable – affiliates		0			0
Other liabilities		23,663			17,600
Total liabilities		153,663			321,229
Shareholders’ equity
Total shareholders’ equity		339,384			434,278
Total liabilities and shareholders’ equity		493,047			755,507
Other Global Indemnity Group, LLC Subsidiaries and Eliminations (non-co-obligor subsidiaries)
ASSETS
Total investments		1,156,475	[2]		1,261,757	[3]
Cash and cash equivalents		20,871	[2]		40,631	[2],[3]	$ 51,611	[3]		$ 71,237	[3]
Investments in subsidiaries		339,384	[2]		434,278	[3]
Due from subsidiaries and affiliates		11,521	[2]		7,577	[3]
Notes receivable – affiliate		0	[2]		445,498	[3]
Interest receivable – affiliate		0	[2]		17,258	[3]
Premiums receivable, net		109,820	[2]		118,035	[3]
Reinsurance receivables, net		112,633	[2]		83,938	[3]
Funds held by ceding insurers		46,894	[2]		48,580	[3]
Federal income taxes receivable		(2,892)	[2]		(3,208)	[3]
Deferred federal income taxes		(3,505)	[2]		(756)	[3]
Deferred acquisition costs		67,470	[2]		70,677	[3]
Intangible assets		21,094	[2]		21,491	[3]
Goodwill		6,521	[2]		6,521	[3]
Prepaid reinsurance premiums		15,558	[2]		16,716	[3]
Other assets		40,854	[2]		45,021	[3]
Total assets		1,942,698	[2]		2,614,014	[3]
Liabilities:
Unpaid losses and loss adjustment expenses		669,930	[2]		630,181	[3]
Unearned premiums		304,074	[2]		314,861	[3]
Ceded balances payable		9,576	[2]		20,404	[3]
Payable for securities purchased		3,423	[2]		850	[3]
Contingent commissions		11,329	[2]		11,928	[3]
Debt		0	[2]		0	[3]
Notes payable – affiliates		11,283	[2]		5,049	[3]
Accrued interest payable – affiliates		16	[2]		1,929	[3]
Other liabilities		53,303	[2]		54,544	[3]
Total liabilities		1,062,934	[2]		1,039,746	[3]
Shareholders’ equity
Total shareholders’ equity		879,764	[2]		1,574,268	[3]
Total liabilities and shareholders’ equity		1,942,698	[2]		2,614,014	[3]
Consolidation Adjustments
ASSETS
Total investments	[4]	0			0
Cash and cash equivalents	[4]	0			0
Investments in subsidiaries	[4]	(1,219,148)			(2,008,546)
Due from subsidiaries and affiliates	[4]	0			0
Notes receivable – affiliate	[4]	(11,283)			(525,547)
Interest receivable – affiliate	[4]	(16)			(22,272)
Premiums receivable, net	[4]	0			0
Reinsurance receivables, net	[4]	0			0
Funds held by ceding insurers	[4]	0			0
Federal income taxes receivable	[4]	0			0
Deferred federal income taxes	[4]	0			0
Deferred acquisition costs	[4]	0			0
Intangible assets	[4]	0			0
Goodwill	[4]	0			0
Prepaid reinsurance premiums	[4]	0			0
Other assets	[4]	(3,747)			(6,989)
Total assets	[4]	(1,234,194)			(2,563,354)
Liabilities:
Unpaid losses and loss adjustment expenses	[4]	0			0
Unearned premiums	[4]	0			0
Ceded balances payable	[4]	0			0
Payable for securities purchased	[4]	0			0
Contingent commissions	[4]	0			0
Debt	[4]	(3,747)			(6,989)
Notes payable – affiliates	[4]	(11,283)			(525,547)
Accrued interest payable – affiliates	[4]	(16)			(22,272)
Other liabilities	[4]	0			0
Total liabilities	[4]	(15,046)			(554,808)
Shareholders’ equity
Total shareholders’ equity	[4]	(1,219,148)			(2,008,546)
Total liabilities and shareholders’ equity	[4]	$ (1,234,194)			$ (2,563,354)

[1] Includes activity for Global Indemnity Limited from January 1, 2020 to August 27, 2020 and activity for Global Indemnity Group, LLC from August 28, 2020 to September 30, 2020

[2] Includes all other subsidiaries of Global Indemnity Group, LLC and eliminations

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

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