XML 94 R75.htm IDEA: XBRL DOCUMENT
v3.20.4

PREMISES AND EQUIPMENT (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Property, Plant and Equipment [Abstract] |  |  |
Depreciation expense | $ 15.2 | $ 15.0 | $ 13.6

X
- Definition Depreciation Adjusted for Discontinued Operations. + References No definition available. + Details
Name: | aub_DepreciationAdjustedForDiscontinuedOperations
Namespace Prefix: | aub_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration