Amount represents average daily securities payable under securities issued repurchase agreement during the year.

No definition available.

Name:	LARK_DebtInstrumentAverageDailyBalance
Namespace Prefix:	LARK_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount represents maximum month end balance under securities issued repurchase agreement during the year.

+ References

No definition available.

+ Details

Name:	LARK_DebtInstrumentMaximumMonthEndBalance
Namespace Prefix:	LARK_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Carrying amount of assets sold under agreements to repurchase when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under repurchase agreements exceeds 10 percent of total assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(m)(1)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(m)(1)(ii)(A)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

+ Details

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

- Definition

The average effective interest rate during the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(a)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1F

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 835
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482925/835-30-45-2

+ Details

Name:	us-gaap_DebtInstrumentInterestRateDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
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

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 860
-SubTopic 30
-Name Accounting Standards Codification
-Section 55
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481395/860-30-55-4

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 860
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481420/860-30-50-7

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481420/860-30-50-7

+ Details

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

- Details

Name:	us-gaap_AssetsSoldUnderAgreementsToRepurchaseAxis=LARK_USFederalTreasuryObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetsSoldUnderAgreementsToRepurchaseAxis=LARK_AgencyMortgageBackedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=LARK_OvernightAndContinuousMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=LARK_UptoThirtyDaysMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=LARK_ThirtyToNinetyDaysMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=LARK_GreaterThanNinetyDaysMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Schedule of Repurchase Agreements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Average daily balance during the year	$ 12,216	$ 18,361
Average interest rate during the year	2.82%	2.72%
Maximum month-end balance during the year	$ 16,660	$ 20,083
Weighted average interest rate at year-end	2.68%	2.84%
Total	$ 13,808	$ 12,714
US Federal Treasury Obligations [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	11,729	12,714
Agency Mortgage Backed [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	2,079
Overnight And Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	13,808	12,714
Overnight And Continuous [Member] \| US Federal Treasury Obligations [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	11,729	12,714
Overnight And Continuous [Member] \| Agency Mortgage Backed [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total	2,079
Upto 30 Days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total
Upto 30 Days [Member] \| US Federal Treasury Obligations [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total
Upto 30 Days [Member] \| Agency Mortgage Backed [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total
30 - 90 Days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total
30 - 90 Days [Member] \| US Federal Treasury Obligations [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total
30 - 90 Days [Member] \| Agency Mortgage Backed [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total
Greater than 90 Days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total
Greater than 90 Days [Member] \| US Federal Treasury Obligations [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total
Greater than 90 Days [Member] \| Agency Mortgage Backed [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Total