CONDENSED FINANCIAL INFORMATION OF AMERIS BANCORP (PARENT COMPANY ONLY) - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
OPERATING ACTIVITIES
Net income	$ 61,248	$ 21,384	$ 38,904	$ 39,905	$ 43,536	$ 41,444	$ 9,387	$ 26,660	$ 161,441	$ 121,027	$ 73,548
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation expense									3,424	6,241	3,316
Increase (decrease) in interest payable									5,855	2,411	1,757
Decrease (increase) in tax receivable									(3,597)	4,032	(473)
Provision for deferred taxes									22,821	1,374	12,430
Other operating activities									41,266	(10,761)	10,895
Net cash used in operating activities									(940,211)	(108,803)	(62,562)
INVESTING ACTIVITIES
Net cash used in investing activities									(487,087)	(53,314)	(666,907)
Financing Activities, net of effects of business combinations
Issuance of common stock									0	0	88,656
Purchase of treasury shares									(18,410)	(2,062)	(886)
Dividends paid - common stock									(24,675)	(16,405)	(14,650)
Proceeds from other borrowings									5,236,572	1,530,000	1,837,692
Repayment of other borrowings									(4,141,349)	(1,844,258)	(2,079,554)
Proceeds from exercise of stock options									5,139	914	2,669
Net cash provided by financing activities									1,369,620	510,986	861,742
Net increase (decrease) in cash and cash equivalents									(57,678)	348,869	132,273
Cash and cash equivalents at beginning of period				679,527				330,658	679,527	330,658	198,385
Cash and cash equivalents at end of period	621,849				679,527				621,849	679,527	330,658
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest									125,373	67,523	32,465
Cash paid (received) during the year for income taxes									35,865	20,026	38,939
Ameris Bancorp
OPERATING ACTIVITIES
Net income									161,441	121,027	73,548
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation expense									3,424	6,241	3,316
Undistributed earnings of subsidiaries									(116,608)	(86,498)	(76,471)
Increase (decrease) in interest payable									33	313	1,142
Decrease (increase) in tax receivable									(6,860)	1,436	5,176
Provision for deferred taxes									1,595	195	(4,620)
Gain on sale of equity security									(61)	0	0
Other operating activities									(2,396)	(2,051)	1,230
Total adjustments									(120,873)	(80,364)	(70,227)
Net cash used in operating activities									40,568	40,663	3,321
INVESTING ACTIVITIES
Proceeds from sale of equity security									282	0	0
Repayment of advances to subsidiary bank									10,000	0	0
Investment in subsidiary									0	0	(110,000)
Net cash proceeds received from (paid for) acquisitions									34,939	(90,542)	0
Net cash used in investing activities									45,221	(90,542)	(110,000)
Financing Activities, net of effects of business combinations
Issuance of common stock									0	0	88,656
Purchase of treasury shares									(18,410)	(2,062)	(886)
Dividends paid - common stock									(24,675)	(16,405)	(14,650)
Proceeds from other borrowings									117,572	70,000	73,692
Repayment of other borrowings									(70,000)	0	(38,850)
Proceeds from exercise of stock options									5,139	914	2,669
Net cash provided by financing activities									9,626	52,447	110,631
Net increase (decrease) in cash and cash equivalents									95,415	2,568	3,952
Cash and cash equivalents at beginning of period				$ 6,977				$ 4,409	6,977	4,409	457
Cash and cash equivalents at end of period	$ 102,392				$ 6,977				102,392	6,977	4,409
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest									16,173	12,357	7,923
Cash paid (received) during the year for income taxes									$ 0	$ (7,500)	$ (11,000)