Note 21 - Comparative Quarterly Financial Data (unaudited) (Detail) - Quarterly financial data: (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
Net revenues (in Dollars)	$ 26,915	$ 34,294	$ 24,450	$ 14,445	$ 1,795	$ 707				$ 100,104	$ 2,502
Gross profit (loss) (in Dollars)	6,668	12,204	9,482	5,686	512	531				34,040	1,043
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 operations, 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
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 operations, 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) attributable to Steel Excel Inc.	$ (0.01)	$ 0.41	$ 1.49	$ (0.17)	$ (0.15)	$ 0.12	$ 0.48	$ 0.17	$ (1.53)	$ 1.71	$ 0.62
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 operations, net of taxes	$ 0.00	$ 0.04	$ (0.01)	$ (0.22)	$ (0.03)		$ 0.63		$ (0.03)	$ (0.16)	$ 0.61
Net income (loss) attributable to Steel Excel Inc.	$ (0.01)	$ 0.41	$ 1.49	$ (0.17)	$ (0.15)	$ 0.12	$ 0.48	$ 0.17	$ (1.53)	$ 1.71	$ 0.62
Shares used for computing income (loss) per share:
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
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