Note 16 - Net Income (Loss) Per Share (Detail) - A Reconciliation of the Numerator and Denominator of the Basic and Diluted Net (Loss) Income Per Share: (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								9 Months Ended	12 Months Ended
	Dec. 31, 2012	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jul. 01, 2011	Apr. 01, 2011	Dec. 31, 2010	Dec. 31, 2012	Dec. 31, 2011
Numerators (basic and diluted):
Income (loss) from continuing operations, net of taxes (in Dollars)	$ 4	$ 4,866	$ 17,429	$ (120)	$ 1,344	$ (1,543)	$ (1,550)	$ 1,817	$ (17,386)	$ 22,179	$ 68
Income (loss) from discontinued opertions, net of taxes (in Dollars)	51	483	(121)	(2,348)	(286)	85	6,830		(373)	(1,935)	6,629
Net income (loss) attributable to Steel Excel Inc. (in Dollars)	$ (76)	$ 5,349	$ 17,308	$ (1,888)	$ (1,663)	$ 1,335	$ 5,280	$ 1,817	$ (17,759)	$ 20,693	$ 6,769
Denominators:
Weighted average shares outstanding - basic (in Shares)	12,984	12,982	11,588	10,891	10,887	10,881	10,881	10,880	11,609	12,110	10,882
Effect of common stock equivalents (if any):
Stock-based awards (in Shares)										23	15
Weighted average shares outstanding - diluted (in Shares)	13,007	13,001	11,605	10,891	10,905	10,905	10,895	10,887	11,609	12,133	10,897
Basic
Income (loss) from continuing operations, net of taxes	$ 0.00	$ 0.37	$ 1.50	$ (0.01)	$ 0.09	$ (0.14)	$ (0.14)	$ 0.17	$ (1.50)	$ 1.83	$ 0.01
Income (loss) from discontinued opertions, net of taxes	$ 0.00	$ 0.04	$ (0.01)	$ (0.22)	$ (0.03)	$ 0.01	$ 0.63		$ (0.03)	$ (0.16)	$ 0.61
Net income (loss)	$ (0.01)	$ 0.41	$ 1.49	$ (0.17)	$ (0.15)	$ 0.12	$ 0.48	$ 0.17	$ (1.53)	$ 1.71	$ 0.62
Diluted
Income (loss) from continuing operations, net of taxes	$ 0.00	$ 0.37	$ 1.50	$ (0.01)	$ 0.09	$ (0.14)	$ (0.14)	$ 0.17	$ (1.50)	$ 1.83	$ 0.01
Income (loss) from discontinued opertions, net of taxes	$ 0.00	$ 0.04	$ (0.01)	$ (0.22)	$ (0.03)		$ 0.63		$ (0.03)	$ (0.16)	$ 0.61
Net income (loss)	$ (0.01)	$ 0.41	$ 1.49	$ (0.17)	$ (0.15)	$ 0.12	$ 0.48	$ 0.17	$ (1.53)	$ 1.71	$ 0.62