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
Mar. 31, 2015	Mar. 31, 2014
Numerators:
Net income (loss)	$ (7,613)	$ 1,967
Non-controlling interest	363	326
Net income (loss) attributable to Steel Excel Inc.	$ (7,250)	$ 2,293
Denominators:
Basic weighted average common shares outstanding (in Shares)	11,475	11,981
Effect of dilutive securities:
Stock-based awards (in Shares)	0	18
Diluted weighted average common shares outstanding (in Shares)	11,475	11,999
Basic income (loss) per share attributable to Steel Excel Inc.:
Net income (loss) (in dollars per share)	$ (0.63)us-gaap_EarningsPerShareBasic	$ 0.19us-gaap_EarningsPerShareBasic
Diluted income (loss) per share attributable to Steel Excel Inc.:
Net income (loss) (in dollars per share)	$ (0.63)us-gaap_EarningsPerShareDiluted	$ 0.19us-gaap_EarningsPerShareDiluted
Antidilutive securities excluded (in shares)	(15)

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

Mar. 31, 2015

Mar. 31, 2014

Numerators:

Net income (loss)

$ (7,613)us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest

$ 1,967us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest

Non-controlling interest

363us-gaap_IncomeLossFromContinuingOperationsAttributableToNoncontrollingEntity

326us-gaap_IncomeLossFromContinuingOperationsAttributableToNoncontrollingEntity

Net income (loss) attributable to Steel Excel Inc.

$ (7,250)us-gaap_IncomeLossFromContinuingOperations

$ 2,293us-gaap_IncomeLossFromContinuingOperations

Denominators:

Basic weighted average common shares outstanding (in Shares)

11,475us-gaap_WeightedAverageNumberOfSharesOutstandingBasic

11,981us-gaap_WeightedAverageNumberOfSharesOutstandingBasic

Effect of dilutive securities:

Stock-based awards (in Shares)

0us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

18us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

Diluted weighted average common shares outstanding (in Shares)

11,475us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding

11,999us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding

Basic income (loss) per share attributable to Steel Excel Inc.:

Net income (loss) (in dollars per share)

$ (0.63)us-gaap_EarningsPerShareBasic

$ 0.19us-gaap_EarningsPerShareBasic

Diluted income (loss) per share attributable to Steel Excel Inc.:

Net income (loss) (in dollars per share)

$ (0.63)us-gaap_EarningsPerShareDiluted

$ 0.19us-gaap_EarningsPerShareDiluted

Antidilutive securities excluded (in shares)

(15)us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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Amount of income (loss) from continuing operations attributable to the noncontrolling interest. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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