Business Combinations - Estimated Fair Value of Assets Acquired and Liabilities Assumed (Detail) (USD $) In Thousands, except Share data, unless otherwise specified				0 Months Ended			0 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Jun. 30, 2014 Coastal Bankshares, Inc. [Member]	Jun. 30, 2014 Coastal Bankshares, Inc. [Member] As Recorded by Acquired Bank [Member]	Jun. 30, 2014 Coastal Bankshares, Inc. [Member] Fair Value Adjustments [Member]	Dec. 23, 2013 Prosperity Banking Company [Member]	Dec. 23, 2013 Prosperity Banking Company [Member] As Recorded by Acquired Bank [Member]	Dec. 23, 2013 Prosperity Banking Company [Member] Fair Value Adjustments [Member]
Assets
Cash and cash equivalents				$ 3,895	$ 3,895		$ 4,285	$ 4,285
Federal funds sold and interest-bearing balances				15,923	15,923		21,687	21,687
Investment securities				66,766	67,266	(500)	152,274	151,863	411
Other investments				975	975		8,727	8,727
Mortgage loans held for sale				7,288	7,288
Loans				279,441	296,141	(16,700)	449,696	487,358	(37,662)
Less allowance for loan losses					(3,218)	3,218		(6,811)	6,811
Loans, net				279,441	292,923	(13,482)	449,696	480,547	(30,851)
Other real estate owned				11,464	14,992	(3,528)	5,623	6,883	(1,260)
Premises and equipment				11,882	11,882		36,293	36,293
Intangible assets				4,773	507	4,266	4,557	174	4,383
Other assets				22,710	22,710		27,792	26,600	1,192
Total assets				425,117	438,361	(13,244)	710,934	737,059	(26,125)
Deposits:
Noninterest-bearing				80,012	80,012		149,242	149,242
Interest-bearing				289,012	289,012		324,441	324,441
Total deposits				369,024	369,024		473,683	473,683
Federal funds purchased and securities sold under agreements to repurchase				5,428	5,428		21,530	21,530
Other borrowings				22,005	22,005		197,313	185,000	12,313
Other liabilities				6,192	6,192		14,513	14,058	455
Subordinated deferrable interest debentures				9,052	15,465	(6,413)	13,197	29,500	(16,303)
Total liabilities				411,701	418,114	(6,413)	720,236	723,771	(3,535)
Net identifiable assets acquired over (under) liabilities assumed				13,416	20,247	(6,831)	(9,302)	13,288	(22,590)
Goodwill	58,903	35,049	956	23,854		23,854	34,093		34,093
Net assets acquired over (under) liabilities assumed				37,270	20,247	17,023	24,791	13,288	11,503
Consideration:
Ameris Bancorp common shares issued				1,598,987	1,598,987		1,168,918	1,168,918
Purchase price per share of the Company's common stock					$ 21.56			$ 21.07
Company common stock issued					34,474			24,629
Cash exchanged for shares					2,796			162
Fair value of total consideration transferred					$ 37,270			$ 24,791