Condensed Financial Information of Ameris Bancorp (Parent Company Only) - Condensed Statements of Operations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income
Gain on sale of securities	$ 322	$ 238	$ 200
Total income	129,479	141,071	119,071
Expense
Interest	15,074	27,547	29,794
Other expense	39,476	38,305	31,849
Total other expenses	119,470	101,953	81,188
Earnings (loss) before income tax benefit and dividends received in excess of earnings of subsidiaries and equity in undistributed income (loss) of subsidiaries	21,720	31,649	(7,184)
Income tax benefit	7,285	10,556	(3,195)
Net income (loss)	14,435	21,093	(3,989)
Preferred stock dividend	3,577	3,241	3,213
Net income (loss) available to common shareholders	10,858	17,852	(7,202)
Parent Company [Member]
Income
Dividends from subsidiaries	29,000
Gain on sale of securities	214
Other income	106	124	59
Total income	29,320	124	59
Expense
Interest	1,489	1,417	887
Other expense	1,545	1,120	1,198
Total other expenses	3,034	2,537	2,085
Earnings (loss) before income tax benefit and dividends received in excess of earnings of subsidiaries and equity in undistributed income (loss) of subsidiaries	26,286	(2,413)	(2,026)
Income tax benefit	921	785	541
Earnings (loss) before equity in undistributed income (loss) of subsidiaries	27,207	(1,628)	(1,485)
Dividends received in excess of earnings of subsidiaries	(12,772)
Equity in undistributed income (loss) of subsidiaries		22,721	(2,504)
Net income (loss)	14,435	21,093	(3,989)
Preferred stock dividend	3,577	3,241	3,213
Net income (loss) available to common shareholders	$ 10,858	$ 17,852	$ (7,202)