Earnings per Share - Calculation (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Computation of basic earnings per share [Abstract]
Net Income for Basic Earnings per Share		$ 2,664	$ 3,478	$ 4,862	$ 9,944
Basic Weighted Average Shares Outstanding (in shares)	[1]	16,931,447	17,851,780	17,310,875	18,000,234
Basic Earnings per Share (in dollars per share)		$ 0.16	$ 0.19	$ 0.28	$ 0.55
Common Class A
Computation of basic earnings per share [Abstract]
Net Income for Basic Earnings per Share		$ 2,661	$ 3,478	$ 4,859	$ 9,944
Basic Weighted Average Shares Outstanding (in shares)		16,914,641	17,851,780	17,301,491	18,000,234
Participating Shares of Restricted Class A Common Stock
Computation of basic earnings per share [Abstract]
Net Income for Basic Earnings per Share		$ 3		$ 3
Basic Weighted Average Shares Outstanding (in shares)	[2]	16,806		9,384

[1] ^{The Company issues restricted shares of Class A common stock and restricted Class B units that have non-forfeitable dividend rights.  Under the "two-class method," these shares and units are considered participating securities and are required to be included in the computation of basic and diluted earnings per share.}

[2] Certain unvested shares of Class A common stock granted to employees have nonforfeitable rights to dividends and therefore participate fully in the results of the Company from the date they are granted. They are included in the computation of basic earnings per share using the two-class method for participating securities.