Nature of Operations and Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Nature of Operations and Summary of Significant Accounting Policies
Service charges on deposit accounts	$ 260	$ 298
Non-deposit brokerage fees	95	$ 99
Cumulative effect	18,307		$ 17,365
Operating lease right-of-use-assets	1,849
Operating lease liabilities	$ 1,892