Computation of Basic and Diluted Loss Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share Reconciliation [Abstract]
Loss from continuing operations	$ (5,687)	$ (2,166)	$ (9,721)	$ (4,683)
Loss from discontinued operations, net of income taxes	(172)	(462)	(827)	(3,082)
Net loss	(5,859)	(2,628)	(10,548)	(7,765)
Loss attributable to noncontrolling interest
Net loss attributable to Signature Group Holdings, Inc.	$ (5,859)	$ (2,628)	$ (10,548)	$ (7,765)
Weighted average basic and diluted shares outstanding	11,883,605	11,632,828	11,843,526	11,545,766
Basic and diluted loss per share:
Continuing operations	$ (0.48)	$ (0.19)	$ (0.82)	$ (0.40)
Discontinued operations	$ (0.01)	$ (0.04)	$ (0.07)	$ (0.27)
Basic and diluted loss per share	$ (0.49)	$ (0.23)	$ (0.89)	$ (0.67)