Investment Securities, Equity Securities Changes in Fair Value Recognized in Net Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Schedule of Trading Securities and Other Trading Assets [Line Items]
Equity Securities, Amortized Cost Basis	$ 2,140	$ 2,110
Equity Securities	2,144	$ 2,160
Net gains (losses) recognized	(23)
Less: net gains (losses) recognized on equity securities sold	23
Unrealized gains (losses) recognized and still held at period end	$ (46)