BUSINESS COMBINATIONS - Narrative (Details) $ / shares in Units, $ in Thousands							12 Months Ended
	Mar. 11, 2016 USD ($) branch $ / shares shares	Jun. 12, 2015 USD ($)	Jun. 12, 2015 USD ($)	Jun. 12, 2015 USD ($)	Jun. 12, 2015 USD ($) branch	May 22, 2015 USD ($) branch	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Business Acquisition [Line Items]
Issuance of common stock in acquisitions							$ 0	$ 72,455	$ 0
Goodwill							$ 125,532	$ 125,532	$ 90,082
Jacksonville Bancorp, Inc
Business Acquisition [Line Items]
Number of bank branches | branch	8
Number of stock for each share of Ameris common stock converted | shares	0.5861
Share price (in dollars per share) | $ / shares	$ 16.50
Stock allocation	75.00%
Cash allocation	25.00%
Common shares issued in a business combination (in shares) | shares	2,549,469
Issuance of common stock in acquisitions	$ 72,455
Cash exchanged for shares	23,937
Goodwill	35,485
Loans purchased	401,600
Discount on loans acquired	$ 15,200
Percentage of discount on loans acquired	3.64%
Accretable yield	$ 27,000
Premises and equipment	4,679
Purchase price	96,392
Jacksonville Bancorp, Inc | As Previously Reported
Business Acquisition [Line Items]
Goodwill	0
Premises and equipment	$ 4,798
Branches from Bank Of America
Business Acquisition [Line Items]
Number of bank branches			18		18
Cash exchanged for shares				$ 20,000
Goodwill		$ 11,210	$ 11,210	11,210	$ 11,210
Accretable yield		$ 364	$ 364	364	364
Deposit premium on deposits assumed			3.00%
Average daily deposits period		15 years
Net of loans acquired		$ 4,000	$ 4,000	4,000	4,000
Premises and equipment		10,653	10,653	10,653	10,653
Fair value of loans acquired		4,000	4,000	4,000	4,000
Purchase price				20,002
Branches from Bank Of America | As Previously Reported
Business Acquisition [Line Items]
Goodwill		0	0	0	0
Premises and equipment		$ 10,348	$ 10,348	$ 10,348	$ 10,348
Merchants and Southern Banks of Florida
Business Acquisition [Line Items]
Number of bank branches | branch						13
Cash exchanged for shares						$ 50,000
Goodwill						14,634
Accretable yield						11,200
Net of loans acquired						8,400
Premises and equipment						10,934
Fair value of loans acquired						191,500
Purchase price						$ 50,000
Estimated discount						4.21%
Merchants and Southern Banks of Florida | As Previously Reported
Business Acquisition [Line Items]
Goodwill						$ 0
Premises and equipment						$ 14,614