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, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
OPERATING ACTIVITIES
Net income	$ 94,285	$ 116,145	$ 32,236	$ 19,322	$ 61,248	$ 21,384	$ 38,904	$ 39,905	$ 261,988	$ 161,441	$ 121,027
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation expense									3,810	3,424	6,241
Increase in interest payable									(6,036)	5,855	2,411
Decrease (increase) in tax receivable									(12,062)	(3,597)	4,032
Provision for deferred taxes									(7,929)	22,821	1,374
Change attributable to other operating activities									(97,730)	40,758	(10,761)
Net cash provided by (used in) operating activities									798,396	(940,211)	(108,803)
INVESTING ACTIVITIES
Proceeds from bank owned life insurance									3,381	7,429	0
Net cash used in investing activities									(1,200,726)	(487,087)	(53,314)
Financing Activities, net of effects of business combinations
Purchase of treasury shares									(7,995)	(18,410)	(2,062)
Dividends paid - common stock									(41,685)	(24,675)	(16,405)
Proceeds from other borrowings									7,202,981	5,236,572	1,530,000
Repayment of other borrowings									(8,176,491)	(4,141,349)	(1,844,258)
Proceeds from exercise of stock options									2,262	5,139	914
Net cash provided by financing activities									1,897,787	1,369,620	510,986
Net increase (decrease) in cash and cash equivalents									1,495,457	(57,678)	348,869
Cash and cash equivalents at beginning of period				621,849				679,527	621,849	679,527	330,658
Cash and cash equivalents at end of period	2,117,306				621,849				2,117,306	621,849	679,527
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest									94,786	125,373	67,523
Cash received during the year for income taxes									98,609	35,865	20,026
Ameris Bancorp
OPERATING ACTIVITIES
Net income									261,988	161,441	121,027
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation expense									3,810	3,424	6,241
Undistributed earnings of subsidiaries									(188,769)	(116,608)	(86,498)
Increase in interest payable									847	33	313
Decrease (increase) in tax receivable									6,001	(6,860)	1,436
Provision for deferred taxes									(1,225)	1,595	195
Gain on sale of equity security									0	(61)	0
Change attributable to other operating activities									7,652	(2,396)	(2,051)
Total adjustments									(171,684)	(120,873)	(80,364)
Net cash provided by (used in) operating activities									90,304	40,568	40,663
INVESTING ACTIVITIES
(Increase) decrease in other investments									(8,012)	282	0
Repayment of advances to subsidiary bank									0	10,000	0
Investment in subsidiary									(75,000)	0	0
Net cash proceeds received from (paid for) acquisitions									0	34,939	(90,542)
Proceeds from bank owned life insurance									2,383	0	0
Net cash used in investing activities									(80,629)	45,221	(90,542)
Financing Activities, net of effects of business combinations
Purchase of treasury shares									(7,995)	(18,410)	(2,062)
Dividends paid - common stock									(41,685)	(24,675)	(16,405)
Proceeds from other borrowings									108,149	117,572	70,000
Repayment of other borrowings									(5,155)	(70,000)	0
Proceeds from exercise of stock options									2,262	5,139	914
Net cash provided by financing activities									55,576	9,626	52,447
Net increase (decrease) in cash and cash equivalents									65,251	95,415	2,568
Cash and cash equivalents at beginning of period				$ 102,392				$ 6,977	102,392	6,977	4,409
Cash and cash equivalents at end of period	$ 167,643				$ 102,392				167,643	102,392	6,977
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest									16,769	16,173	12,357
Cash received during the year for income taxes									$ (10,000)	$ 0	$ (7,500)