Other Real Estate Assets Owned (OREO) Other Real Estate Assets Owned (OREO) - Major Classifications (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other real estate	$ 3,871	$ 4,051	$ 3,424
Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other real estate	853	871
Secured by farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other real estate	0	0
Secured by 1-4 family residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other real estate	1,598	1,035
Other real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other real estate	$ 1,420	$ 2,145