LOANS AND ALLOWANCE FOR LOAN LOSSES - Rollforward of Accretable Discounts of Purchased Loans (Details) - Purchased Loans, Accretable Discount - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance, January 1	$ 40,496	$ 20,192
Additions due to acquisitions	38,116	30,037
Reduction due to purchase of acquired formerly serviced portfolio	(750)	0
Accretion	(20,255)	(11,918)
Accretable discounts removed due to charge-offs	0	(42)
Transfers between non-accretable and accretable discounts, net	1,678	2,227
Ending balance	$ 59,285	$ 40,496

Certain loans acquired in transfer accounted for as debt securities non accretable and accretable discounts net.

No definition available.

Name:	abcb_CertainLoansAcquiredInTransferAccountedForAsDebtSecuritiesNonAccretableAndAccretableDiscountsNet
Namespace Prefix:	abcb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Certain Loans Acquired In Transfer Not Accounted For As Debt Securities, Accretable Yield, Reduction From Purchase Of Acquired Formerly Serviced Portfolio

+ References

No definition available.

+ Details

Name:	abcb_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldReductionFromPurchaseOfAcquiredFormerlyServicedPortfolio
Namespace Prefix:	abcb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretable Discounts Removed Due To Charge Offs

+ References

No definition available.

+ Details

Name:	abcb_CertainLoansAcquiredinTransferNotAccountedforasDebtSecuritiesAccretableYieldAccretableDiscountsRemovedDueToChargeOffs
Namespace Prefix:	abcb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=118938799&loc=d3e13503-111538

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=118939070&loc=d3e15032-111544

+ Details

Name:	us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYield
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of accretion recognized for the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities, with evidence of deterioration of credit quality.

+ References

+ Details

Name:	us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAccretion
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of additions to the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

+ Details

Name:	us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAccretableYieldAdditions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=abcb_PurchasedLoansAccretableDiscountMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: