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		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 2,495	$ 4,506	$ 4,021	$ 4,991
Total Gains or Losses Included in Other Comprehensive Income	(3)	(1)	(26)	(16)
Maturities / Calls	(1,995)	(475)	(3,498)	(945)
Purchases	0	0	0	0
Balance of Recurring Level 3 Assets at September 30	$ 497	$ 4,030	$ 497	$ 4,030