Deposits - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Deposit Liabilities [Abstract]
Deposits obtained through brokers	$ 195.2	$ 236.7

Domestic Deposit, Brokered Certificates Of Deposits

No definition available.

Name:	lbai_DomesticDepositBrokeredCertificatesOfDeposits
Namespace Prefix:	lbai_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant