Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (23,763)us-gaap_ProfitLoss	$ 10,851us-gaap_ProfitLoss	$ 20,244us-gaap_ProfitLoss
Other comprehensive income (loss):
Foreign currency translation adjustment	20	(63)	(100)
Reclassification to realized gains	0	(361)	0
Net foreign currency translation adjustment	20	(424)	(100)
Marketable securities:
Gross unrealized gains (losses) on marketable securities, net of tax	(20,043)	7,636	506
Reclassification to realized gains, net of tax	(5,223)	(1,642)	(203)
Net unrealized gain (loss) on marketable securities, net of taxes	(25,266)	5,994	303
Comprehensive income (loss)	(49,009)	16,421	20,447
Comprehensive loss (income) attributable to non-controlling interest	(44)	3,344	449
Comprehensive income (loss) attributable to Steel Excel Inc.	(49,053)us-gaap_ComprehensiveIncomeNetOfTax	19,765us-gaap_ComprehensiveIncomeNetOfTax	20,896us-gaap_ComprehensiveIncomeNetOfTax
Tax provision on gross unrealized gains (losses)	0	(4,490)	(196)
Tax benefit on reclassifications to realized gains (losses)	$ 0	$ 966	$ 79

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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