Acquired Credit Impaired Loans Loans Acquired in Business Combination, Not Considered Impaired (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	May 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield	$ 773	$ 633		$ 669	$ 813	$ 851	$ 1,080
Columbus First Bancorp, Inc. [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Business Combination, Acquired Receivables, Gross Contractual Amount			$ 281,639
Business Combination, Acquired Receivables, Fair Value Adjustment			1,801
Business Combination, Acquired Receivable, Fair Value	$ 282,133	$ 282,748	279,838
Business Combination, Acquired Receivables, Estimated Uncollectible			1,905
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, Contractually Required Payments Receivable at Acquisition			4,989
Certain Loans Acquired in Transfer, Nonaccretable Difference			906
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, Cash Flows Expected to be Collected at Acquisition			4,083
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield			151
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, at Fair Value			$ 3,932