Commitments and Contingencies (Additional Information) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loss Contingencies [Line Items]
Operating Leases, Rent Expense	$ 6.4us-gaap_LeaseAndRentalExpense	$ 4.0us-gaap_LeaseAndRentalExpense	$ 4.0us-gaap_LeaseAndRentalExpense
Lydall Gerhardi [Member] \| Unfavorable Regulatory Action [Member]
Loss Contingencies [Line Items]
Maximum fine percentage of revenue	10.00%

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

No definition available.

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration