BUSINESS COMBINATIONS - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ / shares in Units, $ in Thousands				12 Months Ended
	Mar. 11, 2016	Jun. 12, 2015	May 22, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deposits:
Goodwill				$ 125,532	$ 125,532	$ 90,082
Consideration:
Company common stock issued				$ 0	$ 72,455	$ 0
Jacksonville Bancorp, Inc
Assets
Cash and cash equivalents	$ 9,704
Federal funds sold and interest-bearing balances	7,027
Investment securities	59,894
Other investments	2,458
Loans	401,638
Less allowance for loan losses	0
Loans, net	401,638
Other real estate owned	1,926
Premises and equipment	4,679
Intangible assets	4,746
Other assets	33,883
Total assets	525,955
Deposits:
Noninterest-bearing	123,399
Interest-bearing	277,960
Total deposits	401,359
Other borrowings	48,434
Subordinated deferrable interest debentures	12,901
Other liabilities	2,354
Total liabilities	465,048
Net identifiable assets acquired over (under) liabilities assumed	60,907
Goodwill	35,485
Net assets acquired over (under) liabilities assumed	$ 96,392
Consideration:
Ameris Bancorp common shares issued	2,549,469
Price per share of the Company's common stock (in dollars per share)	$ 28.42
Company common stock issued	$ 72,455
Cash exchanged for shares	23,937
Fair value of total consideration transferred	96,392
Jacksonville Bancorp, Inc | Initial Fair Value Adjustments
Assets
Cash and cash equivalents	0
Federal funds sold and interest-bearing balances	0
Investment securities	(942)
Other investments	0
Loans	(15,746)
Less allowance for loan losses	12,613
Loans, net	(3,133)
Other real estate owned	(1,035)
Premises and equipment	0
Intangible assets	5,566
Other assets	23,266
Total assets	23,722
Deposits:
Noninterest-bearing	0
Interest-bearing	421
Total deposits	421
Other borrowings	84
Subordinated deferrable interest debentures	(3,393)
Other liabilities	0
Total liabilities	(2,888)
Net identifiable assets acquired over (under) liabilities assumed	26,610
Goodwill	31,375
Net assets acquired over (under) liabilities assumed	57,985
Jacksonville Bancorp, Inc | Subsequent Fair Value Adjustments
Assets
Cash and cash equivalents	0
Federal funds sold and interest-bearing balances	0
Investment securities	0
Other investments	0
Loans	553
Less allowance for loan losses	0
Loans, net	553
Other real estate owned	88
Premises and equipment	(119)
Intangible assets	(1,108)
Other assets	(3,524)
Total assets	(4,110)
Deposits:
Noninterest-bearing	0
Interest-bearing	0
Total deposits	0
Other borrowings	0
Subordinated deferrable interest debentures	0
Other liabilities	0
Total liabilities	0
Net identifiable assets acquired over (under) liabilities assumed	(4,110)
Goodwill	4,110
Net assets acquired over (under) liabilities assumed	0
Jacksonville Bancorp, Inc | As Previously Reported
Assets
Cash and cash equivalents	9,704
Federal funds sold and interest-bearing balances	7,027
Investment securities	60,836
Other investments	2,458
Loans	416,831
Less allowance for loan losses	(12,613)
Loans, net	404,218
Other real estate owned	2,873
Premises and equipment	4,798
Intangible assets	288
Other assets	14,141
Total assets	506,343
Deposits:
Noninterest-bearing	123,399
Interest-bearing	277,539
Total deposits	400,938
Other borrowings	48,350
Subordinated deferrable interest debentures	16,294
Other liabilities	2,354
Total liabilities	467,936
Net identifiable assets acquired over (under) liabilities assumed	38,407
Goodwill	0
Net assets acquired over (under) liabilities assumed	$ 38,407
Branches from Bank Of America
Assets
Cash and cash equivalents		$ 630,220
Loans		3,999
Premises and equipment		10,653
Intangible assets		8,636
Other assets		126
Total assets		653,634
Deposits:
Noninterest-bearing		149,854
Interest-bearing		494,895
Total deposits		644,749
Other liabilities		93
Total liabilities		644,842
Net identifiable assets acquired over (under) liabilities assumed		8,792
Goodwill		11,210
Net assets acquired over (under) liabilities assumed		20,002
Consideration:
Cash exchanged for shares		20,000
Cash paid as deposit premium		20,002
Fair value of total consideration transferred		20,002
Branches from Bank Of America | Initial Fair Value Adjustments
Assets
Cash and cash equivalents		0
Loans		0
Premises and equipment		1,060
Intangible assets		7,651
Other assets		0
Total assets		8,711
Deposits:
Noninterest-bearing		0
Interest-bearing		(215)
Total deposits		(215)
Other liabilities		0
Total liabilities		(215)
Net identifiable assets acquired over (under) liabilities assumed		8,926
Goodwill		11,076
Net assets acquired over (under) liabilities assumed		20,002
Branches from Bank Of America | Subsequent Fair Value Adjustments
Assets
Cash and cash equivalents		0
Loans		(364)
Premises and equipment		(755)
Intangible assets		985
Other assets		0
Total assets		(134)
Deposits:
Noninterest-bearing		0
Interest-bearing		0
Total deposits		0
Other liabilities		0
Total liabilities		0
Net identifiable assets acquired over (under) liabilities assumed		(134)
Goodwill		134
Net assets acquired over (under) liabilities assumed		0
Branches from Bank Of America | As Previously Reported
Assets
Cash and cash equivalents		630,220
Loans		4,363
Premises and equipment		10,348
Intangible assets		0
Other assets		126
Total assets		645,057
Deposits:
Noninterest-bearing		149,854
Interest-bearing		495,110
Total deposits		644,964
Other liabilities		93
Total liabilities		645,057
Net identifiable assets acquired over (under) liabilities assumed		0
Goodwill		0
Net assets acquired over (under) liabilities assumed		$ 0
Merchants and Southern Banks of Florida
Assets
Cash and cash equivalents			$ 7,527
Federal funds sold and interest-bearing balances			106,188
Investment securities			163,229
Other investments			619
Loans			191,546
Less allowance for loan losses			0
Loans, net			191,546
Other real estate owned			2,967
Premises and equipment			10,934
Intangible assets			3,943
Other assets			3,559
Total assets			490,512
Deposits:
Noninterest-bearing			121,708
Interest-bearing			327,700
Total deposits			449,408
Federal funds purchased and securities sold under agreements to repurchase			0
Subordinated deferrable interest debentures			3,506
Other liabilities			2,232
Total liabilities			455,146
Net identifiable assets acquired over (under) liabilities assumed			35,366
Goodwill			14,634
Net assets acquired over (under) liabilities assumed			50,000
Consideration:
Cash exchanged for shares			50,000
Fair value of total consideration transferred			50,000
Merchants and Southern Banks of Florida | Initial Fair Value Adjustments
Assets
Cash and cash equivalents			0
Federal funds sold and interest-bearing balances			0
Investment securities			(553)
Other investments			0
Loans			(8,500)
Less allowance for loan losses			3,354
Loans, net			(5,146)
Other real estate owned			(1,115)
Premises and equipment			(3,680)
Intangible assets			4,577
Other assets			2,335
Total assets			(3,582)
Deposits:
Noninterest-bearing			0
Interest-bearing			0
Total deposits			0
Federal funds purchased and securities sold under agreements to repurchase			0
Subordinated deferrable interest debentures			(2,680)
Other liabilities			81
Total liabilities			(2,599)
Net identifiable assets acquired over (under) liabilities assumed			(983)
Goodwill			12,090
Net assets acquired over (under) liabilities assumed			11,107
Merchants and Southern Banks of Florida | Subsequent Fair Value Adjustments
Assets
Cash and cash equivalents			0
Federal funds sold and interest-bearing balances			0
Investment securities			(639)
Other investments			(253)
Loans			91
Less allowance for loan losses			0
Loans, net			91
Other real estate owned			0
Premises and equipment			0
Intangible assets			(634)
Other assets			(1,109)
Total assets			(2,544)
Deposits:
Noninterest-bearing			0
Interest-bearing			41,588
Total deposits			41,588
Federal funds purchased and securities sold under agreements to repurchase			(41,588)
Subordinated deferrable interest debentures			0
Other liabilities			0
Total liabilities			0
Net identifiable assets acquired over (under) liabilities assumed			(2,544)
Goodwill			2,544
Net assets acquired over (under) liabilities assumed			0
Merchants and Southern Banks of Florida | As Previously Reported
Assets
Cash and cash equivalents			7,527
Federal funds sold and interest-bearing balances			106,188
Investment securities			164,421
Other investments			872
Loans			199,955
Less allowance for loan losses			(3,354)
Loans, net			196,601
Other real estate owned			4,082
Premises and equipment			14,614
Intangible assets			0
Other assets			2,333
Total assets			496,638
Deposits:
Noninterest-bearing			121,708
Interest-bearing			286,112
Total deposits			407,820
Federal funds purchased and securities sold under agreements to repurchase			41,588
Subordinated deferrable interest debentures			6,186
Other liabilities			2,151
Total liabilities			457,745
Net identifiable assets acquired over (under) liabilities assumed			38,893
Goodwill			0
Net assets acquired over (under) liabilities assumed			$ 38,893