Principal Activity and Significant Accounting Policies - Earnings Per Common Share And Incurred But Not Reported Insurance Liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Earnings per Common Share
Dilutive potential common shares	0	0
Denominators for the basic and diluted earnings per common share	9,562,000	9,091,000
Accrued expenses and other liabilities
Incurred but Not Reported Insurance Liability
Property claim reserves	$ 510		$ 204