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		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Reconciliation of the numerator and denominator of the basic and diluted net (loss) income per share: [Abstract]
Net income from continuing operations	$ 886	$ 17,430	$ 3,860	$ 17,310
Numerators:
Continuing operations	185	0	521	0
Net income	1,071	17,430	4,381	17,310
Loss from discontinued operations, net of taxes	0	(121)	0	(2,470)
Discontinued operations	0	0	0	580
Loss from discontinued operations, net of taxes, attributable to Steel Excel Inc.	0	(121)	0	(1,890)
Net income attributable to Steel Excel Inc.	$ 1,071	$ 17,309	$ 4,381	$ 15,420
Denominators:
Basic weighted average common shares outstanding (in Shares)	12,718	11,588	12,796	11,240
Effect of dilutive securities:
Stock-based awards (in Shares)	16	17	16	17
Diluted weighted average common shares outstanding (in Shares)	12,734	11,605	12,812	11,257
Basic income (loss) per share attributable to Steel Excel Inc.:
Net income from continuing operations (in dollars per share)	$ 0.08	$ 1.50	$ 0.34	$ 1.54
Loss from discontinued operations, net of taxes (in dollars per share)	$ 0.00	$ (0.01)	$ 0.00	$ (0.17)
Net income (in dollars per share)	$ 0.08	$ 1.49	$ 0.34	$ 1.37
Diluted income (loss) per share attributable to Steel Excel Inc.:
Net income from continuing operations (in dollars per share)	$ 0.08	$ 1.50	$ 0.34	$ 1.54
Loss from discontinued operations, net of taxes (in dollars per share)	$ 0.00	$ (0.01)	$ 0.00	$ (0.17)
Net income (in dollars per share)	$ 0.08	$ 1.49	$ 0.34	$ 1.37