XML 67 R56.htm IDEA: XBRL DOCUMENT
v3.21.1

Note 11 - Regulatory Matters - Actual Capital Amounts and Ratios (Details) $ in Thousands | Mar. 31, 2021 USD ($) | Dec. 31, 2020 USD ($)
--- | --- | ---
Boone Bank and Trust [Member] |  |
Tier one leverage capital | $ 14,162 | $ 13,967
Tier one leverage capital to average assets | 0.094 | 0.092
Tier one leverage capital required to be well capitalized | $ 12,790 | $ 12,170
Tier one leverage capital required to be well capitalized to average assets | 0.085 | 0.080
First National Bank [Member] | Also Conducts Business Out of 3 Full Service Offices in Des Moines Metro Area [Member] |  |
Tier one leverage capital | $ 88,178 | $ 86,071
Tier one leverage capital to average assets | 0.085 | 0.086
Tier one leverage capital required to be well capitalized | $ 88,123 | $ 80,393
Tier one leverage capital required to be well capitalized to average assets | 0.085 | 0.080
Iowa State Savings Bank [Member] |  |
Tier one leverage capital | $ 21,947 | $ 21,610
Tier one leverage capital to average assets | 0.093 | 0.094
Tier one leverage capital required to be well capitalized | $ 20,057 | $ 18,321
Tier one leverage capital required to be well capitalized to average assets | 0.085 | 0.080
Reliance State Bank [Member] | Conducts Business Out of Offices at Story City, Garner, and Kleme, Iowa [Member] |  |
Tier one leverage capital | $ 23,671 | $ 23,278
Tier one leverage capital to average assets | 0.091 | 0.094
Tier one leverage capital required to be well capitalized | $ 22,015 | $ 19,741
Tier one leverage capital required to be well capitalized to average assets | 0.085 | 0.080
State Bank and Trust [Member] |  |
Tier one leverage capital | $ 17,292 | $ 16,564
Tier one leverage capital to average assets | 0.084 | 0.085
Tier one leverage capital required to be well capitalized | $ 17,485 | $ 15,657
Tier one leverage capital required to be well capitalized to average assets | 0.085 | 0.080
United Bank and Trust [Member] |  |
Tier one leverage capital | $ 10,727 | $ 10,539
Tier one leverage capital to average assets | 0.091 | 0.092
Tier one leverage capital required to be well capitalized | $ 9,972 | $ 9,180
Tier one leverage capital required to be well capitalized to average assets | 0.085 | 0.080

X
- Definition Amount of Tier 1 leverage capital as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneLeverageCapital
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of minimum Tier 1 leverage capital categorized as well capitalized as defined by regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Ratio of minimum Tier 1 leverage capital to average assets categorized as well capitalized as defined by regulatory framework for prompt corrective action. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Ratio of Tier 1 capital to average assets as defined by regulatory framework. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826 + Details
Name: | us-gaap_TierOneLeverageCapitalToAverageAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=atlo_BooneBankAndTrustMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=atlo_FirstNationalBankMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementScenarioAxis=atlo_AlsoConductsBusinessOutOf3FullServiceOfficesInDesMoinesMetroAreaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=atlo_IowaStateSavingsBankMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=atlo_RelianceStateBankMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementScenarioAxis=atlo_ConductsBusinessOutOfOfficesAtStoryCityGarnerAndKlemeIowaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=atlo_StateBankAndTrustMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=atlo_UnitedBankAndTrustMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |