Inventories - Narrative (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Gross tooling inventory	$ 20.2	$ 10.3
Tooling inventory, net of progress billings	$ 18.5	$ 9.4

The net amount of tooling inventory after the deduction of progress billings as of the balance sheet date.

No definition available.

Name:	ldl_ToolingInventoryNetOfProgressBillings
Namespace Prefix:	ldl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant