Inventories - Additional Information (Detail)	3 Months Ended
Sep. 30, 2015 USD ($)
Inventory Disclosure [Abstract]
Cumulative effect of change in inventory cost	$ 160,000
Effect of change in inventory cost on income from continuing operations	$ 107,000

Cumulative effect of the change from LIFO to FIFO method of valuing inventory, net of tax effect.

No definition available.

Name:	sli_EffectOfLifoToFifoChangeNet
Namespace Prefix:	sli_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration