Business Combinations - Estimated Fair Value of Assumed Assets Acquired and Liabilities of Prosperity (Detail) (USD $) In Thousands, except Share data, unless otherwise specified			0 Months Ended		0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 23, 2013 Prosperity Banking Company [Member]	Dec. 23, 2013 Prosperity Banking Company [Member] Fair Value Adjustments [Member]	Dec. 23, 2013 Prosperity Banking Company [Member] As Recorded by Prosperity [Member]
Assets
Cash and cash equivalents			$ 4,285		$ 4,285
Federal funds sold and interest bearing balances			21,687		21,687
Investment securities			152,274	411	151,863
Other investments			8,727		8,727
Loans			449,696	(37,662)	487,358
Less allowance for loan losses				6,811	(6,811)
Loans, net			449,696	(30,851)	480,547
Other real estate owned and repossessed assets			5,623	(1,260)	6,883
Premises and equipment			36,293		36,293
Intangible assets			4,557	4,383	174
Other assets			27,792	1,192	26,600
Total assets acquired			710,934	(26,125)	737,059
Deposits:
Noninterest-bearing			149,242		149,242
Interest-bearing			324,441		324,441
Total deposits			473,683		473,683
Federal funds purchased and securities sold under agreements to repurchase			21,530		21,530
Other borrowings			197,313	12,313	185,000
Other liabilities			14,513	455	14,058
Subordinated deferrable interest debentures			13,197	(16,303)	29,500
Total liabilities assumed			720,236	(3,535)	723,771
Net identifiable assets acquired over (under) liabilities assumed			(9,302)	(22,590)	13,288
Goodwill	35,049	956	34,093	34,093
Net assets acquired over (under) liabilities assumed			24,791	11,503	13,288
Consideration:
Ameris Bancorp common shares issued			1,168,918		1,168,918
Purchase price per share of the Company's common stock					$ 21.07
Company common stock issued					24,629
Cash exchanged for shares					162
Fair value of total consideration transferred					$ 24,791