Regulatory Matters - Company's and Bank's Actual Capital Amounts and Ratios (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Consolidated [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital to Risk Weighted Assets To Be Well Capitalized Under Prompt corrective Action Provisions Ratio
Tier I Capital to Risk Weighted Assets To Be Well Capitalized Under Prompt corrective Action Provisions Ratio
Tier I Capital to Average Assets To Be Well Capitalized Under Prompt corrective Action Provisions Ratio
Total Capital to Risk Weighted Assets For capital adequacy purposes ratio	8.00%	8.00%
Tier I Capital to Risk Weighted Assets For capital adequacy purposes ratio	4.00%	4.00%
Tier I Capital to Average Assets For capital adequacy purposes ratio	4.00%	4.00%
Total Capital to Risk Weighted Assets For capital adequacy purposes amount	$ 141,516	$ 137,954
Tier I Capital to Risk Weighted Assets For capital adequacy purposes amount	70,758	68,977
Tier I Capital to Average Assets For capital adequacy purposes amount	119,660	120,683
Total Capital to Risk Weighted Assets Actual Ratio	18.74%	20.05%
Tier I Capital to Risk Weighted Assets Actual Ratio	17.49%	18.80%
Tier I Capital to Average Assets Actual Ratio	10.34%	10.76%
Total Capital to Risk Weighted Assets Actual Amount	331,545	345,789
Tier I Capital to Risk Weighted Assets Actual Amount	309,415	324,125
Tier I Capital to Average Assets Actual Amount	309,415	324,125
Ameris Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital to Risk Weighted Assets To Be Well Capitalized Under Prompt corrective Action Provisions Ratio	10.00%	10.00%
Tier I Capital to Risk Weighted Assets To Be Well Capitalized Under Prompt corrective Action Provisions Ratio	6.00%	6.00%
Tier I Capital to Average Assets To Be Well Capitalized Under Prompt corrective Action Provisions Ratio	5.00%	5.00%
Total Capital to Risk Weighted Assets To Be Well Capitalized Under Prompt corrective Action Provisions Amount	176,717	171,976
Tier I Capital to Risk Weighted Assets To Be Well Capitalized Under Prompt corrective Action Provisions Amount	106,030	103,185
Tier I Capital to Average Assets To Be Well Capitalized Under Prompt corrective Action Provisions Amount	149,299	150,643
Total Capital to Risk Weighted Assets For capital adequacy purposes ratio	8.00%	8.00%
Tier I Capital to Risk Weighted Assets For capital adequacy purposes ratio	4.00%	4.00%
Tier I Capital to Average Assets For capital adequacy purposes ratio	4.00%	4.00%
Total Capital to Risk Weighted Assets For capital adequacy purposes amount	141,374	137,580
Tier I Capital to Risk Weighted Assets For capital adequacy purposes amount	70,687	68,790
Tier I Capital to Average Assets For capital adequacy purposes amount	119,440	120,515
Total Capital to Risk Weighted Assets Actual Ratio	18.65%	19.87%
Tier I Capital to Risk Weighted Assets Actual Ratio	17.40%	18.61%
Tier I Capital to Average Assets Actual Ratio	10.30%	10.62%
Total Capital to Risk Weighted Assets Actual Amount	329,578	341,697
Tier I Capital to Risk Weighted Assets Actual Amount	307,470	320,032
Tier I Capital to Average Assets Actual Amount	$ 307,470	$ 320,032