Goodwill and Intangibles - Summary of Other Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 17,898	$ 17,682
Accumulated Amortization	(8,677)	(7,599)
Net Intangible Assets	9,221	10,083
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	10,245	10,246
Accumulated Amortization	(5,067)	(4,512)
Net Intangible Assets	5,178	5,734
CB&T Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	3,142	3,142
Accumulated Amortization	(1,279)	(1,181)
Net Intangible Assets	1,863	1,961
Array and Arrow Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	2,353	2,353
Accumulated Amortization	(1,022)	(847)
Net Intangible Assets	1,331	1,506
Mortgage Servicing Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	1,508	1,430
Accumulated Amortization	(1,013)	(949)
Net Intangible Assets	495	481
Alliance Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	650	511
Accumulated Amortization	(296)	(110)
Net Intangible Assets	$ 354	$ 401