Premises and Equipment and Lease Commitments (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Lease liabilities - operating leases		$ 8,495
Right-of-use assets acquired in the exchange for lease liability upon adoption of ASC 842		$ 8,400
Weighted average remaining lease term		18 years 9 months
Operating lease, discount rate		3.50%
Operating lease		$ 854
Operating lease payment	$ 740
Operating leases, rent expense		854	$ 974	$ 761
Gain (loss) on disposition of property plant equipment		(1)	$ 0	0
Small Office Condo [Member]
Property, Plant and Equipment [Line Items]
Long lived assets to be disposed of fair value		$ 430
Proceeds from sale of property, plant, and equipment				392
Gain (loss) on disposition of property plant equipment				$ 47
Minimum
Property, Plant and Equipment [Line Items]
Operating lease term		2 months
Maximum
Property, Plant and Equipment [Line Items]
Operating lease term		25 years