Mortgage Banking - Capitalized Mortgage and Valuation Allowance (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Mortgage servicing assets:
Balance at beginning of period	$ 10,458	$ 10,297	$ 10,419	$ 10,240
Loans sold, servicing retained	738	438	1,454	1,164
Amortization	(579)	(340)	(1,256)	(1,009)
Carrying value before valuation allowance at end of period	10,617	10,395	10,617	10,395
Valuation allowance:
Balance at beginning of period	(603)	(349)	(300)	(432)
Impairment recovery (charges)	(155)	8	(458)	91
Balance at end of period	(758)	(341)	(758)	(341)
Net carrying value of MSRs at end of period	9,859	10,054	9,859	10,054
Fair value of MSRs at end of period	$ 9,859	$ 10,558	$ 9,859	$ 10,558