Subsequent Event (Details) $ / shares in Units, $ in Thousands	Jan. 01, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares	Dec. 28, 2017 $ / shares	Dec. 31, 2016 $ / shares
Subsequent Event [Line Items]
Common Stock Par Or Stated Value Per Share | $ / shares		$ 0.01		$ 0.01
Share Price | $ / shares			$ 38.78
County First Acquisition [Member]
Subsequent Event [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets | $		$ 227,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans Receivable Assets | $		143,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposit Receivable Assets | $		200,000
Business Acquisition, Transaction Costs | $		$ 829
Subsequent Event [Member] | County First Acquisition [Member]
Subsequent Event [Line Items]
Common Stock Par Or Stated Value Per Share | $ / shares	$ 1.00
Business Acquisition, Share Price | $ / shares	2.20
Business Acquisition, Share Price, Cash Consideration | $ / shares	1.00
Business Acquisition, Share Price, Contingent Cash Consideration | $ / shares	$ 1.20
Payments to Acquire Businesses, Gross | $	$ 2,100
Business Combination, Consideration Transferred | $	$ 37,700
Subsequent Event [Member] | County First Acquisition [Member] | Common Stock [Member]
Subsequent Event [Line Items]
Business Acquisition Share Convertion Rate	0.9543
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares | shares	919,000