Fair Value (Reconciliation of all Assets Measured at Fair Value on Recurring Basis, Using Significant Unobservable Inputs (Level 3) (Details) - Fair Value, Measurements, Recurring - Obligations of State and Political Subdivisions - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance of Recurring Level 3 Assets at January 1	$ 4,991	$ 5,649
Total Gains or Losses Included in Other Comprehensive Income	(9)	(18)
Maturities / Calls	(470)	(460)
Acquired through Bank Acquisition	0	0
Balance of Recurring Level 3 Assets at March 31	$ 4,512	$ 5,171