Business Combinations - Estimated Fair Value of Assets Acquired and Liabilities Assumed (Detail) - USD ($)	Jun. 12, 2015	May. 22, 2015	Jun. 30, 2014	Jun. 30, 2015	Dec. 31, 2014
Assets
Cash value of bank owned life insurance			$ 57,864,000	$ 59,552,000	$ 58,867,000
Deposits:
Federal funds purchased and securities sold under agreements to repurchase				13,400,000
Goodwill			58,903,000	87,367,000	$ 63,547,000
Bank of America [Member]
Assets
Cash and cash equivalents	$ 630,220,000
Loans	4,363,000
Premises and equipment	11,408,000
Intangible assets	7,651,000
Other assets	126,000
Total assets	653,768,000
Deposits:
Noninterest-bearing	149,854,000
Interest-bearing	494,895,000
Total deposits	644,749,000
Other liabilities	93,000
Total liabilities	644,842,000
Net identifiable assets acquired over (under) liabilities assumed	8,926,000
Goodwill	11,076,000			11,100,000
Net assets acquired over (under) liabilities assumed	20,002,000
Consideration:
Cash exchanged for shares	20,000,000
Bank of America [Member] | As Recorded by Acquired Bank [Member]
Assets
Cash and cash equivalents	630,220,000
Loans	4,363,000
Premises and equipment	10,348,000
Other assets	126,000
Total assets	645,057,000
Deposits:
Noninterest-bearing	149,854,000
Interest-bearing	495,110,000
Total deposits	644,964,000
Other liabilities	93,000
Total liabilities	645,057,000
Consideration:
Cash exchanged for shares	20,002,000
Fair value of total consideration transferred	20,002,000
Bank of America [Member] | Initial Fair Value Adjustments [Member]
Assets
Premises and equipment	1,060,000
Intangible assets	7,651,000
Total assets	8,711,000
Deposits:
Interest-bearing	(215,000)
Total deposits	(215,000)
Total liabilities	(215,000)
Net identifiable assets acquired over (under) liabilities assumed	8,926,000
Goodwill	11,076,000
Net assets acquired over (under) liabilities assumed	$ 20,002,000
Merchants and Southern Banks of Florida [Member]
Assets
Cash and cash equivalents		$ 7,527,000
Federal funds sold and interest-bearing balances		106,188,000
Investment securities		163,868,000
Other investments		872,000
Loans		191,455,000
Loans, net		191,455,000
Other real estate owned		2,967,000
Premises and equipment		10,934,000
Intangible assets		4,577,000
Other assets		4,668,000
Total assets		493,056,000
Deposits:
Noninterest-bearing		121,708,000
Interest-bearing		286,112,000
Total deposits		407,820,000
Federal funds purchased and securities sold under agreements to repurchase		41,588,000
Other liabilities		2,232,000
Subordinated deferrable interest debentures		3,506,000
Total liabilities		455,146,000
Net identifiable assets acquired over (under) liabilities assumed		37,910,000
Goodwill		12,090,000		12,100,000
Net assets acquired over (under) liabilities assumed		50,000,000
Consideration:
Fair value of total consideration transferred		50,000,000
Merchants and Southern Banks of Florida [Member] | As Recorded by Acquired Bank [Member]
Assets
Cash and cash equivalents		7,527,000
Federal funds sold and interest-bearing balances		106,188,000
Investment securities		164,421,000
Other investments		872,000
Loans		199,955,000
Less allowance for loan losses		(3,354,000)
Loans, net		196,601,000
Other real estate owned		4,082,000
Premises and equipment		14,614,000
Other assets		2,333,000
Total assets		496,638,000
Deposits:
Noninterest-bearing		121,708,000
Interest-bearing		286,112,000
Total deposits		407,820,000
Federal funds purchased and securities sold under agreements to repurchase		41,588,000
Other liabilities		2,151,000
Subordinated deferrable interest debentures		6,186,000
Total liabilities		457,745,000
Net identifiable assets acquired over (under) liabilities assumed		38,893,000
Net assets acquired over (under) liabilities assumed		38,893,000
Consideration:
Cash exchanged for shares		50,000,000
Fair value of total consideration transferred		50,000,000
Merchants and Southern Banks of Florida [Member] | Initial Fair Value Adjustments [Member]
Assets
Investment securities		(553,000)
Loans		(8,500,000)
Less allowance for loan losses		3,354,000
Loans, net		(5,146,000)
Other real estate owned		(1,115,000)
Premises and equipment		(3,680,000)
Intangible assets		4,577,000
Other assets		2,335,000
Total assets		(3,582,000)
Deposits:
Other liabilities		81,000
Subordinated deferrable interest debentures		(2,680,000)
Total liabilities		(2,599,000)
Net identifiable assets acquired over (under) liabilities assumed		(983,000)
Goodwill		12,090,000
Net assets acquired over (under) liabilities assumed		$ 11,107,000
Coastal Bankshares, Inc. [Member]
Assets
Cash and cash equivalents			3,895,000
Federal funds sold and interest-bearing balances			15,923,000
Investment securities			66,766,000
Other investments			975,000
Mortgage loans held for sale			7,288,000
Loans			279,441,000
Loans, net			279,441,000
Other real estate owned			8,057,000
Premises and equipment			11,882,000
Intangible assets			4,542,000
Cash value of bank owned life insurance			7,812,000
Other assets			14,297,000
Total assets			420,878,000
Deposits:
Noninterest-bearing			80,012,000
Interest-bearing			289,012,000
Total deposits			369,024,000
Federal funds purchased and securities sold under agreements to repurchase			5,428,000
Other borrowings			22,005,000
Other liabilities			6,192,000
Subordinated deferrable interest debentures			9,052,000
Total liabilities			411,701,000
Net identifiable assets acquired over (under) liabilities assumed			9,177,000
Goodwill			28,093,000	$ 28,100,000
Net assets acquired over (under) liabilities assumed			$ 37,270,000
Consideration:
Ameris Bancorp common shares issued			1,598,998
Coastal Bankshares, Inc. [Member] | As Recorded by Acquired Bank [Member]
Assets
Cash and cash equivalents			$ 3,895,000
Federal funds sold and interest-bearing balances			15,923,000
Investment securities			67,266,000
Other investments			975,000
Mortgage loans held for sale			7,288,000
Loans			296,141,000
Less allowance for loan losses			(3,218,000)
Loans, net			292,923,000
Other real estate owned			14,992,000
Premises and equipment			11,882,000
Intangible assets			507,000
Cash value of bank owned life insurance			7,812,000
Other assets			14,898,000
Total assets			438,361,000
Deposits:
Noninterest-bearing			80,012,000
Interest-bearing			289,012,000
Total deposits			369,024,000
Federal funds purchased and securities sold under agreements to repurchase			5,428,000
Other borrowings			22,005,000
Other liabilities			6,192,000
Subordinated deferrable interest debentures			15,465,000
Total liabilities			418,114,000
Net identifiable assets acquired over (under) liabilities assumed			20,247,000
Net assets acquired over (under) liabilities assumed			$ 20,247,000
Consideration:
Ameris Bancorp common shares issued			1,598,998
Purchase price per share of the Company's common stock			$ 21.56
Company common stock issued			$ 34,474,000
Cash exchanged for shares			2,796,000
Fair value of total consideration transferred			37,270,000
Coastal Bankshares, Inc. [Member] | Initial Fair Value Adjustments [Member]
Assets
Investment securities			(500,000)
Loans			(16,700,000)
Less allowance for loan losses			3,218,000
Loans, net			(13,482,000)
Other real estate owned			(3,528,000)
Intangible assets			4,266,000
Total assets			(13,244,000)
Deposits:
Subordinated deferrable interest debentures			(6,413,000)
Total liabilities			(6,413,000)
Net identifiable assets acquired over (under) liabilities assumed			(6,831,000)
Goodwill			23,854,000
Net assets acquired over (under) liabilities assumed			17,023,000
Coastal Bankshares, Inc. [Member] | Subsequent Fair Value Adjustments [Member]
Assets
Other real estate owned			(3,407,000)
Intangible assets			(231,000)
Other assets			(601,000)
Total assets			(4,239,000)
Deposits:
Net identifiable assets acquired over (under) liabilities assumed			(4,239,000)
Goodwill			$ 4,239,000