XML 66 R51.htm IDEA: XBRL DOCUMENT
v3.19.1

Investment Securities - Schedule of Available for Sale Securities Continuous Unrealized Loss Position Fair Value (Details) $ in Thousands | Dec. 31, 2018 USD ($) Number | Dec. 31, 2017 USD ($) Number
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
No. of securities | Number | 490 | 345
Fair value, Less than 12 months | $ 74,366 | $ 134,700
Unrealized losses, Less than 12 months | (536) | (1,022)
Fair value, 12 months or longer | 221,001 | 89,790
Unrealized losses, 12 months or longer | (5,579) | (2,001)
Total, Fair value | 295,367 | 224,490
Total, Unrealized losses | $ (6,115) | $ (3,023)
US Treasury Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
No. of securities | Number | 1 | 1
Fair value, Less than 12 months |  | $ 1,990
Unrealized losses, Less than 12 months |  | (9)
Fair value, 12 months or longer | 1,971 |
Unrealized losses, 12 months or longer | (28) |
Total, Fair value | 1,971 | 1,990
Total, Unrealized losses | $ (28) | $ (9)
US Federal Agency Obligations [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
No. of securities | Number | 6 | 14
Fair value, Less than 12 months | $ 145 | $ 7,989
Unrealized losses, Less than 12 months | (1) | (24)
Fair value, 12 months or longer | 7,970 | 8,272
Unrealized losses, 12 months or longer | (40) | (61)
Total, Fair value | 8,115 | 16,261
Total, Unrealized losses | $ (41) | $ (85)
Municipal Obligations, Tax Exempt [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
No. of securities | Number | 296 | 178
Fair value, Less than 12 months | $ 35,898 | $ 37,299
Unrealized losses, Less than 12 months | (367) | (273)
Fair value, 12 months or longer | 85,921 | 31,930
Unrealized losses, 12 months or longer | (2,403) | (807)
Total, Fair value | 121,819 | 69,229
Total, Unrealized losses | $ (2,770) | $ (1,080)
Municipal Obligations, Taxable [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
No. of securities | Number | 86 | 73
Fair value, Less than 12 months | $ 8,293 | $ 18,792
Unrealized losses, Less than 12 months | (22) | (96)
Fair value, 12 months or longer | 28,984 | 9,744
Unrealized losses, 12 months or longer | (301) | (120)
Total, Fair value | 37,277 | 28,536
Total, Unrealized losses | $ (323) | $ (216)
Agency Mortgage-backed Securities [Member] |  |
Debt Securities, Available-for-sale [Line Items] |  |
No. of securities | Number | 101 | 79
Fair value, Less than 12 months | $ 30,030 | $ 68,630
Unrealized losses, Less than 12 months | (146) | (620)
Fair value, 12 months or longer | 96,155 | 39,844
Unrealized losses, 12 months or longer | (2,807) | (1,013)
Total, Fair value | 126,185 | 108,474
Total, Unrealized losses | $ (2,953) | $ (1,633)

X
- Definition Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for less than twelve months. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for twelve months or longer. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- 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_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=LARK_USFederalAgencyObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=LARK_MunicipalObligationsTaxExemptMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=LARK_MunicipalObligationsTaxableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=LARK_AgencyMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |