Summary of Business Segment Information (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016		Mar. 31, 2015		Dec. 31, 2015
Revenues:
Gross premiums written		$ 141,366		$ 142,869
Net premiums written		116,872		126,104
Net premiums earned		121,636		127,337
Other income		956		552
Total revenues		122,592		127,889
Losses and Expenses:
Net losses and loss adjustment expenses		64,784		69,619
Acquisition costs and other underwriting expenses		52,090		48,258
Income (loss) from segments		5,718		10,012
Unallocated Items:
Net investment income		9,746		8,241
Net realized investment losses		(7,493)		(2,970)
Corporate and other operating expenses		(3,803)		(11,540)
Interest expense		(2,215)		(505)
Income before income taxes		1,953		3,238
Income tax benefit		5,172		3,556
Net income		7,125		6,794
Total assets		1,966,649		2,273,900		$ 1,957,294
Reinsurance Operations
Revenues:
Gross premiums written	[1]	12,735		19,865
Net premiums written	[1]	12,735		19,826
Net premiums earned	[1]	12,217		13,201
Other income	[1]	94		(79)
Total revenues	[1]	12,311		13,122
Losses and Expenses:
Net losses and loss adjustment expenses	[1]	4,605		4,098
Acquisition costs and other underwriting expenses	[1]	4,483		4,889
Income (loss) from segments	[1]	3,223		4,135
Unallocated Items:
Total assets	[1],[2]	697,455		988,161
Commercial Lines
Revenues:
Gross premiums written	[3]	49,091		49,793
Net premiums written	[3]	43,558		45,622
Net premiums earned	[3]	47,333		50,714
Other income	[3]	163		165
Total revenues	[3]	47,496		50,879
Losses and Expenses:
Net losses and loss adjustment expenses	[3]	25,006		29,603
Acquisition costs and other underwriting expenses	[3]	20,471	[4]	20,623	[5]
Income (loss) from segments	[3]	2,019		653
Unallocated Items:
Total assets	[3]	774,062		775,898
Personal Lines
Revenues:
Gross premiums written	[3]	79,540		73,211
Net premiums written	[3]	60,579		60,656
Net premiums earned	[3]	62,086		63,422
Other income	[3]	699		466
Total revenues	[3]	62,785		63,888
Losses and Expenses:
Net losses and loss adjustment expenses	[3]	35,173		35,918
Acquisition costs and other underwriting expenses	[3]	27,136	[6]	22,746	[7]
Income (loss) from segments	[3]	476		5,224
Unallocated Items:
Total assets	[3]	$ 495,132		$ 509,841

[1] External business only, excluding business assumed from affiliates.

[2] Comprised of Global Indemnity Reinsurance's total assets less its investment in subsidiaries.

[3] Includes business ceded to the Company's Reinsurance Operations.

[4] Includes federal excise tax of $127 relating to cessions from Commercial Lines to Reinsurance Operations.

[5] Includes federal excise tax of $268 relating to cessions from Commercial Lines to Reinsurance Operations.

[6] Includes federal excise tax of $311 relating to cessions from Personal Lines to Reinsurance Operations.

[7] Includes federal excise tax of $317 relating to cessions from Personal Lines to Reinsurance Operations.