Net Income (Loss) Per Share - Reconciliation of the numerator and denominator of the basic and diluted net (loss) income per share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reconciliation of the numerator and denominator of the basic and diluted net (loss) income per share: [Abstract]
Net income from continuing operations	$ 2,159	$ 4,865	$ 6,019	$ 22,175
Numerators:
Continuing operations	311	0	832	0
Net income	2,470	4,865	6,851	22,175
Income (loss) from discontinued operations, net of taxes	0	484	0	(1,986)
Discontinued operations	0	0	0	580
Loss from discontinued operations, net of taxes, attributable to Steel Excel Inc.	0	484	0	(1,406)
Net income attributable to Steel Excel Inc.	$ 2,470	$ 5,349	$ 6,851	$ 20,769
Denominators:
Basic weighted average common shares outstanding (in Shares)	12,529	12,982	12,736	11,820
Effect of dilutive securities:
Stock-based awards (in Shares)	17	19	18	20
Diluted weighted average common shares outstanding (in Shares)	12,546	13,001	12,754	11,840
Basic income (loss) per share attributable to Steel Excel Inc.:
Net income from continuing operations (in dollars per share)	$ 0.20	$ 0.37	$ 0.54	$ 1.88
Income (loss) from discontinued operations, net of taxes (in dollars per share)	$ 0.00	$ 0.04	$ 0.00	$ (0.12)
Net income (in dollars per share)	$ 0.20	$ 0.41	$ 0.54	$ 1.76
Diluted income (loss) per share attributable to Steel Excel Inc.:
Net income from continuing operations (in dollars per share)	$ 0.20	$ 0.37	$ 0.54	$ 1.87
Income (loss) from discontinued operations, net of taxes (in dollars per share)	$ 0.00	$ 0.04	$ 0.00	$ (0.12)
Net income (in dollars per share)	$ 0.20	$ 0.41	$ 0.54	$ 1.75