XML 76 R65.htm IDEA: XBRL DOCUMENT
v3.21.1

COMMITMENTS AND CONTINGENCIES (Narrative) (Details) - USD ($) $ in Millions | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Deposits with other financial institutions | $ 176.5 | $ 290.5
Uninsured deposits with other financial institutions | 19.7 | 36.4
Reserve for Off-balance Sheet Activities |  |
Off-balance sheet credit risks, amount, liability | 13.6 | 10.8
Cash Flow Hedging |  |
Deposits with other financial institutions serves as collateral for cash flow hedge | $ 153.8 | $ 251.0

X
- Definition Deposits with other financial institutions. + References No definition available. + Details
Name: | aub_DepositsWithOtherFinancialInstitutions
Namespace Prefix: | aub_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Deposits with other financial institutions serves as collateral for cash flow hedge. + References No definition available. + Details
Name: | aub_DepositsWithOtherFinancialInstitutionsServesAsCollateralForCashFlowHedge
Namespace Prefix: | aub_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of cash as of the balance sheet date that is not insured by the Federal Deposit Insurance Corporation. + References No definition available. + Details
Name: | us-gaap_CashUninsuredAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column B)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column E)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 + Details
Name: | us-gaap_ValuationAllowancesAndReservesBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_ReserveForOffBalanceSheetActivitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |