Acquisitions - Schedule of Acquired Loan Data (Details) - USD ($) $ in Thousands	Jul. 14, 2017	May 19, 2017
IAB
Business Acquisition [Line Items]
Basis in loans at acquisition date	$ 4,838
Contractually required payments receivable at acquisition date	14,131
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, Cash Flows Not Expected to be Collected at Acquisition	8,352
Business Combination, Acquired Receivable, Fair Value	720,544
Business Combination, Acquired Receivables, Gross Contractual Amount	864,613
Business Combination, Acquired Receivables, Estimated Uncollectible	$ 9,786
Arlington Bank
Business Acquisition [Line Items]
Basis in loans at acquisition date		$ 2,625
Contractually required payments receivable at acquisition date		6,183
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, Cash Flows Not Expected to be Collected at Acquisition		2,891
Business Combination, Acquired Receivable, Fair Value		222,055
Business Combination, Acquired Receivables, Gross Contractual Amount		308,857
Business Combination, Acquired Receivables, Estimated Uncollectible		$ 2,741