Consolidated balance sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Class A Common Stock
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock shares authorized (in shares)	300,000,000	300,000,000
Common stock shares issued (in shares)	15,238,079	13,799,630
Common stock shares outstanding (in shares)	15,238,079	13,799,630
Class B Common Stock
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock shares authorized (in shares)	50,000,000	50,000,000
Common stock shares issued (in shares)	21,054,935	22,485,747
Common stock shares outstanding (in shares)	21,054,935	22,485,747