Business Combination (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Aug. 31, 2015
Business Acquisition [Line Items]
Shares of CSBQ common stock outstanding as of August 31, 2015		$ 6,643,341
Market price of CSBQ common stock on August 31, 2015		$ 3.85
Estimated fair value of CSBQ common stock	$ 25,577,000
Estimated fair value of CSBQ stock options	2,858,000
Total consideration	28,435,000
Fair value of assets acquired and liabilities assumed:
Cash and cash equivalents	33,502,000
Investment securities available for sale	74,254,000
Loans	314,827,000
Premises and equipment	9,019,000
Bank owned life insurance	1,278,000
Core deposit intangible	2,750,000
Other real estate owned	5,672,000
Prepaid and other assets	4,301,000
Deposits	(349,462,000)
Securities sold under agreements to repurchase	(17,622,000)
FHLB advances and other borrowings	(42,307,000)
Payables and other liabilities	(11,943,000)
Total fair value of net assets acquired	24,269,000
Goodwill	$ 4,166,000