Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Deferred income tax - unrealized gains (losses) on available for sale securities	$ 2,460	$ 5,135
Deferred income tax - pension adjustments	292	42
Increase in deferred income tax expense	10,054	$ 1,811
State income tax rate effective (as a percent)		2.50%
Pre-1988 tax bad debt reserve	$ 6,869	$ 6,869