Financial Asset Acquired with Credit Deterioration

No definition available.

Name:	lbai_FinancialAssetAcquiredwithCreditDeterioration
Namespace Prefix:	lbai_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

+ Details

Name:	us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(d))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB Topic 6.L.1)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707

+ Details

Name:	us-gaap_LoansAndLeasesReceivableAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

+ Details

Name:	us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_ValuationAllowancesAndReservesTypeAxis=lbai_LoansAndLeasesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=lbai_CommercialIndustrialAndOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_FinanceLeasesPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=lbai_ConstructionRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=lbai_HomeEquityAndConsumerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Loans and Other Real Estate - Allowance for Loan and Lease Losses by Portfolio Segment (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	$ 4,925,998		$ 4,460,447
Ending Balance: Individually evaluated for impairment, related allowance	226		338
Ending Balance	38,655	$ 38,662	37,688	$ 37,293	$ 36,604	$ 35,455
Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Ending Balance: Individually evaluated for impairment	17,653		19,702
Ending Balance: Collectively evaluated for impairment	4,896,140		4,440,093
Ending Balance: Loans acquired with deteriorated credit quality	12,205		652
Total Loans	4,925,998		4,460,447
Ending Balance: Individually evaluated for impairment, related allowance	226		338
Ending Balance: Collectively evaluated for impairment, related allowance	38,429		37,350
Ending Balance	38,655		37,688
Commercial, secured by real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	3,442,973		3,057,779
Ending Balance: Individually evaluated for impairment, related allowance	201		307
Ending Balance	28,525	28,095	27,881	27,646	26,174	25,704
Commercial, secured by real estate \| Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Ending Balance: Individually evaluated for impairment	13,820		16,554
Ending Balance: Collectively evaluated for impairment	3,422,451		3,040,573
Ending Balance: Loans acquired with deteriorated credit quality	6,702		652
Total Loans	3,442,973		3,057,779
Ending Balance: Individually evaluated for impairment, related allowance	201		307
Ending Balance: Collectively evaluated for impairment, related allowance	28,324		27,574
Ending Balance	28,525		27,881
Commercial, industrial and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	391,486		336,735
Ending Balance: Individually evaluated for impairment, related allowance	6		7
Ending Balance	2,458	2,633	1,742	1,968	2,012	2,313
Commercial, industrial and other \| Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Ending Balance: Individually evaluated for impairment	749		1,360
Ending Balance: Collectively evaluated for impairment	389,576		335,375
Ending Balance: Loans acquired with deteriorated credit quality	1,161		0
Total Loans	391,486		336,735
Ending Balance: Individually evaluated for impairment, related allowance	6		7
Ending Balance: Collectively evaluated for impairment, related allowance	2,452		1,735
Ending Balance	2,458		1,742
Equipment finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	104,689		87,925
Ending Balance: Individually evaluated for impairment, related allowance	11		14
Ending Balance	1,110	1,055	987	886	1,264	630
Equipment finance \| Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Ending Balance: Individually evaluated for impairment	25		331
Ending Balance: Collectively evaluated for impairment	104,664		87,594
Ending Balance: Loans acquired with deteriorated credit quality	0		0
Total Loans	104,689		87,925
Ending Balance: Individually evaluated for impairment, related allowance	11		14
Ending Balance: Collectively evaluated for impairment, related allowance	1,099		973
Ending Balance	1,110		987
Real estate - residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	337,482		329,854
Ending Balance: Individually evaluated for impairment, related allowance	3		4
Ending Balance	1,604	1,606	1,566	1,487	1,585	1,557
Real estate - residential mortgage \| Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Ending Balance: Individually evaluated for impairment	2,364		730
Ending Balance: Collectively evaluated for impairment	334,721		329,124
Ending Balance: Loans acquired with deteriorated credit quality	397		0
Total Loans	337,482		329,854
Ending Balance: Individually evaluated for impairment, related allowance	3		4
Ending Balance: Collectively evaluated for impairment, related allowance	1,601		1,562
Ending Balance	1,604		1,566
Real estate - construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	306,440		319,545
Ending Balance: Individually evaluated for impairment, related allowance	0		0
Ending Balance	2,561	2,708	3,015	2,901	3,063	2,731
Real estate - construction \| Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Ending Balance: Individually evaluated for impairment	0		0
Ending Balance: Collectively evaluated for impairment	303,016		319,545
Ending Balance: Loans acquired with deteriorated credit quality	3,424		0
Total Loans	306,440		319,545
Ending Balance: Individually evaluated for impairment, related allowance	0		0
Ending Balance: Collectively evaluated for impairment, related allowance	2,561		3,015
Ending Balance	2,561		3,015
Home equity and consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	342,928		328,609
Ending Balance: Individually evaluated for impairment, related allowance	5		6
Ending Balance	2,397	$ 2,565	2,497	$ 2,405	$ 2,506	$ 2,520
Home equity and consumer \| Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Ending Balance: Individually evaluated for impairment	695		727
Ending Balance: Collectively evaluated for impairment	341,712		327,882
Ending Balance: Loans acquired with deteriorated credit quality	521		0
Total Loans	342,928		328,609
Ending Balance: Individually evaluated for impairment, related allowance	5		6
Ending Balance: Collectively evaluated for impairment, related allowance	2,392		2,491
Ending Balance	$ 2,397		$ 2,497