Loan Servicing (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Transfers and Servicing of Financial Assets [Abstract]
Serviced sold mortgage loans	$ 1,380,000	$ 1,360,000	$ 1,380,000	$ 1,360,000	$ 1,370,000
Serviced sold mortgage loans with recourse	2,600	3,200	2,600	3,200	$ 3,000
Servicing fees included in other service income	900	$ 800	2,700	$ 2,600
Mortgage Loans Sold with Recourse, Reserve	$ 49		$ 49