Assets Acquired in FDIC-Assisted Acquisitions - Components of Covered Assets (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended		12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Dec. 31, 2012
Covered Assets [Line Items]
Covered loans	$ 367,735	$ 529,792	$ 443,322
Less: Fair value adjustments	36,485	86,275	53,085
Total covered loans	331,250	443,517	390,237
OREO	46,468	75,960	55,827
Less: Fair value adjustments	8,042	13,782	9,934
Total covered OREO	38,426	62,178	45,893
Total covered assets	369,676	505,695	436,130
FDIC indemnification asset	49,180	105,513	65,441	159,724
American United Bank (AUB) [Member]
Covered Assets [Line Items]
Covered loans	9,106	23,721	15,787
Less: Fair value adjustments	133	2,114	231
Total covered loans	8,973	21,607	15,556
OREO	1,690	4,847	4,264
Total covered OREO	1,690	4,847	4,264
Total covered assets	10,663	26,454	19,820
FDIC indemnification asset	1,676	4,526	1,452
United Security Bank (USB) [Member]
Covered Assets [Line Items]
Covered loans	14,030	23,298	18,504
Less: Fair value adjustments	805	2,552	1,427
Total covered loans	13,225	20,746	17,077
OREO	2,927	4,127	2,865
Less: Fair value adjustments	62	140	141
Total covered OREO	2,865	3,987	2,724
Total covered assets	16,090	24,733	19,801
FDIC indemnification asset	920	5,802	889
Satilla Community Bank (SCB) [Member]
Covered Assets [Line Items]
Covered loans	30,545	38,478	34,637
Less: Fair value adjustments	954	2,882	1,483
Total covered loans	29,591	35,596	33,154
OREO	3,332	4,655	3,461
Less: Fair value adjustments	308	306	303
Total covered OREO	3,024	4,349	3,158
Total covered assets	32,615	39,945	36,312
FDIC indemnification asset	3,073	4,603	3,175
First Bank of Jacksonville (FBJ) [Member]
Covered Assets [Line Items]
Covered loans	23,264	29,154	25,891
Less: Fair value adjustments	2,696	5,086	3,730
Total covered loans	20,568	24,068	22,161
OREO	1,734	2,037	1,880
Less: Fair value adjustments	135	209	242
Total covered OREO	1,599	1,828	1,638
Total covered assets	22,167	25,896	23,799
FDIC indemnification asset	2,752	5,632	3,689
Darby Bank & Trust (DBT) [Member]
Covered Assets [Line Items]
Covered loans	81,700	132,707	105,157
Less: Fair value adjustments	8,774	27,386	17,819
Total covered loans	72,926	105,321	87,338
OREO	12,766	23,594	17,023
Less: Fair value adjustments	913	2,003	1,282
Total covered OREO	11,853	21,591	15,741
Total covered assets	84,779	126,912	103,079
FDIC indemnification asset	10,119	27,957	18,724
Tifton Banking Company (TBC) [Member]
Covered Assets [Line Items]
Covered loans	28,363	37,560	32,590
Less: Fair value adjustments	1,853	3,299	2,354
Total covered loans	26,510	34,261	30,236
OREO	4,493	7,069	4,844
Less: Fair value adjustments	758	1,650	745
Total covered OREO	3,735	5,419	4,099
Total covered assets	30,245	39,680	34,335
FDIC indemnification asset	3,543	6,083	3,721
High Trust Bank (HTB) [Member]
Covered Assets [Line Items]
Covered loans	59,267	74,867	67,126
Less: Fair value adjustments	6,535	9,747	7,359
Total covered loans	52,732	65,120	59,767
OREO	4,130	10,868	6,374
Less: Fair value adjustments	1,349	3,436	2,304
Total covered OREO	2,781	7,432	4,070
Total covered assets	55,513	72,552	63,837
FDIC indemnification asset	9,000	13,314	9,325
One Georgia Bank (OGB) [Member]
Covered Assets [Line Items]
Covered loans	49,501	70,644	58,512
Less: Fair value adjustments	4,937	11,568	5,067
Total covered loans	44,564	59,076	53,445
OREO	7,964	10,244	7,506
Less: Fair value adjustments	2,984	3,948	2,984
Total covered OREO	4,980	6,296	4,522
Total covered assets	49,544	65,372	57,967
FDIC indemnification asset	7,268	14,591	9,645
Central Bank of Georgia (CBG) [Member]
Covered Assets [Line Items]
Covered loans	71,959	99,363	85,118
Less: Fair value adjustments	9,798	21,641	13,615
Total covered loans	62,161	77,722	71,503
OREO	7,432	8,519	7,610
Less: Fair value adjustments	1,533	2,090	1,933
Total covered OREO	5,899	6,429	5,677
Total covered assets	68,060	84,151	77,180
FDIC indemnification asset	$ 10,829	$ 23,005	$ 14,821