Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Redeemable Series C Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	3,440,690	3,440,690
Preferred stock, shares outstanding	3,440,690	3,440,690
Preferred stock, liquidation value	$ 17,203	$ 17,203
Class A
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	59,779,750	59,779,750
Common stock, shares issued	7,949,152	7,849,756
Common stock, shares outstanding	7,863,582	7,764,186
Treasury stock, shares	85,570	85,570
Class B
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	220,250	220,250
Common stock, shares issued	220,250	220,250
Common stock, shares outstanding	220,250	220,250