CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Jun. 30, 2020	Dec. 31, 2019
Convertible preferred stock issued	0	0
Class A Common Stock
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	65,603,746	64,733,667
Common stock, shares outstanding	30,965,255	31,105,000
Treasury stock, shares	34,638,491	33,628,667
Class B common stock
Common stock, par value (usd per share)	$ 0.01
Common stock, shares authorized	30,000,000
Common stock, shares issued	12,029,375