The percentage of cost method investment ownership.

No definition available.

Name:	abcb_CostMethodInvestmentOwnershipPercentage
Namespace Prefix:	abcb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the amount of letter of credit issued by a financial institution which acts as a guarantee of payment to a beneficiary, or as the source of payment for a specific transaction.

+ References

No definition available.

+ Details

Name:	abcb_LetterOfCredit
Namespace Prefix:	abcb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount awarded to other party in judgment or settlement of litigation.

+ References

No definition available.

+ Details

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

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

- Definition

Amount of liabilities classified as other.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.15)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_OtherLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of shares of stock issued during the period as part of a transaction to acquire assets that do not qualify as a business combination.

+ References

No definition available.

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesPurchaseOfAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Value of shares of stock issued during the period as part of a transaction to acquire assets that do not qualify as a business combination.

+ References

No definition available.

+ Details

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

- Details

Name:	dei_LegalEntityAxis=abcb_FederalHomeLoanBankMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=abcb_UsPremiumFinancingHoldingCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=abcb_UsPremiumFinancingHoldingCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=abcb_Mr.VillariMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

COMMITMENTS AND CONTINGENT LIABILITIES - Narrative (Details) - USD ($) $ in Thousands	Jan. 03, 2018	Aug. 08, 2013	Dec. 31, 2018	Dec. 31, 2017
Loss Contingencies [Line Items]
Other liabilities			$ 57,023	$ 50,334
Loss contingency, damages sought, value		$ 2,900
Federal Home Loan Bank \| Letter of Credit
Loss Contingencies [Line Items]
Letter of credit			75,000
US Premium Financing Holding Company
Loss Contingencies [Line Items]
Other liabilities			$ 18,100
US Premium Financing Holding Company
Loss Contingencies [Line Items]
Cost method investment ownership percentage	25.01%
Mr. Villari
Loss Contingencies [Line Items]
Cash paid for purchase of shares of common stock	$ 12,500
Stock issued during period, shares, purchase of assets (in shares)	114,285