Commitments and Contingencies - Narrative (Details)				3 Months Ended		6 Months Ended
	Jul. 09, 2019 USD ($)	Apr. 13, 2018 USD ($)	Feb. 28, 2017 USD ($)	Jun. 30, 2020 USD ($) claim	Mar. 31, 2020 USD ($)	Jun. 30, 2020 USD ($) defendant claim	Dec. 31, 2019 USD ($)	Sep. 18, 2017 USD ($)
Loss Contingencies [Line Items]
Insurance recoveries					$ 17,500,000
Estimated insurance recoveries	$ 10,000,000
Accrued liabilities
Loss Contingencies [Line Items]
Accrual for environmental matters				$ 2,620,000		$ 2,620,000
Other Noncurrent Liabilities
Loss Contingencies [Line Items]
Accrual for environmental matters				24,815,000		24,815,000
Handy & Harman Ltd. (HNH)
Loss Contingencies [Line Items]
Accrual for environmental matters				$ 26,055,000		$ 26,055,000
Settlement amount	$ 30,000,000
BNS Subsidiary
Loss Contingencies [Line Items]
Claims, litigation matters (in number of claims) | claim				30,000		30,000
BNS Subsidiary | Insurance Claims
Loss Contingencies [Line Items]
Accrual relating to open and active claims				$ 1,349,000		$ 1,349,000	$ 1,349,000
Minimum | BNS Subsidiary
Loss Contingencies [Line Items]
Loss contingency, number of defendants (in defendants) | defendant						100,000
Adjacent Parcel | Environmental and Other Matters
Loss Contingencies [Line Items]
Accrual increase				$ 14,000,000
Adjacent Parcel | Environmental and Other Matters | Minimum | Handy & Harman Ltd. (HNH)
Loss Contingencies [Line Items]
Environmental exit costs, additional loss			$ 10,500,000
Adjacent Parcel | Environmental and Other Matters | Maximum | Handy & Harman Ltd. (HNH)
Loss Contingencies [Line Items]
Environmental exit costs, additional loss			$ 17,500,000
Costs | Former Owner / Operator | Environmental and Other Matters
Loss Contingencies [Line Items]
Ownership responsibility for site investigation and remediation costs percentage allocation				75.00%		75.00%
Costs | Hhem and HandH
Loss Contingencies [Line Items]
Accrual for environmental matters				$ 1,400,000		$ 1,400,000
Investigation and remediation costs						$ 8,900,000
Costs | Hhem and HandH | Environmental and Other Matters
Loss Contingencies [Line Items]
Ownership responsibility for site investigation and remediation costs percentage allocation				25.00%		25.00%
Payments						$ 1,000,000
Investigation and remediation costs						2,900,000
Camden | SLI
Loss Contingencies [Line Items]
Accrual for environmental matters				$ 2,600,000		2,600,000
Counteroffer						300,000
Camden - Past And Future Expenses | SLI
Loss Contingencies [Line Items]
Damages claimed								$ 1,800,000
Wayne facility | SLI
Loss Contingencies [Line Items]
Accrual for environmental matters				$ 1,400,000		$ 1,400,000
Selling, General and Administrative Expenses | Handy & Harman Ltd. (HNH)
Loss Contingencies [Line Items]
Settlement expense					$ 12,500,000
Preferred stock | Steel Connect, Inc (STCN)
Loss Contingencies [Line Items]
Stock acquired		$ 35,000,000