Investment Securities, Available-for-sale Securities, Transaction Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Proceeds from sales and calls of securities available for sale, gross realized gains and gross realized losses [Abstract]
Proceeds from sales	$ 0	$ 0	$ 0	$ 0
Proceeds from calls	15,444	35,554	64,925	109,123
Gross realized gains	0	0	0	0
Gross realized losses	0	0	0	0
Sales of available for sale securities	$ 0	$ 0	$ 0	$ 0