Non-Binding Proposal to Acquire SL Industries - Additional Information (Detail) - Handy & Harman Ltd. [Member] - Non-Binding Proposal [Member]	Sep. 30, 2015 $ / shares
Business Acquisition [Line Items]
Aggregate consideration percentage, cash	55.00%
Aggregate consideration percentage, stock	45.00%
Minimum [Member]
Business Acquisition [Line Items]
Common stock outstanding, price per share	$ 43.00
Maximum [Member]
Business Acquisition [Line Items]
Common stock outstanding, price per share	$ 45.00