Acquisition of Northwest Georgia Bank - Additional Information (Details)		3 Months Ended		9 Months Ended
	Sep. 18, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) Branch	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Business Acquisition [Line Items]
Business combination, bargain purchase gain			$ 2,794,000		$ 2,794,000
Business combination, deferred taxes		$ 19,704,000		$ 19,704,000		$ 2,831,000
Merger and conversion		1,122,000	291,000	$ 3,268,000	578,000
Northwest Georgia Bank
Business Acquisition [Line Items]
Business acquisition, effective date of acquisition				Sep. 18, 2015
Business acquisition, date of acquisition agreement				Apr. 27, 2015
Number of branches operated prior to acquisition | Branch				6
Cash purchase price	$ 1,500,000
Business combination, bargain purchase gain	2,794,000
Core deposit intangible asset	$ 4,931,000
Estimated useful life of intangible assets	10 years
Business combination, deferred taxes	$ 0
Deferred tax liability recorded in bargain purchase gain	$ 191,000
Number of years of deductibility for income tax of the core deposit intangible	15 years
Merger and conversion		$ 1,122,000	$ 291,000	$ 3,268,000	$ 578,000