Nature of the Business and Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Income tax provision	$ 3,660	$ 7,743	$ 11,580	$ 8,911
BNS Liquidating Trust (BNS Liquidating Trust)
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership (as a percent)	84.90%		84.90%		84.90%
CoSine Communications, Inc. (CoSine)
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership (as a percent)	80.60%		80.60%		48.30%
DGT Holdings Corp. (DGT)
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership (as a percent)	82.70%		82.70%		82.70%
Handy & Harman Ltd. (HNH)
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership (as a percent)	66.10%		66.10%		66.20%
SPH Services, Inc. (SPH Services)
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership (as a percent)	100.00%		100.00%		100.00%
Steel Excel Inc. (Steel Excel)
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership (as a percent)	57.10%		57.10%		57.90%
Steel Excel Inc. (Steel Excel) | Restatement Adjustment | Income Tax Expense
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Income tax provision			$ 3,500
WebFinancial Holding Corporation (WebFinancial)
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership (as a percent)	100.00%		100.00%		100.00%