Shareholder's Equity - Organization structure (Details)	3 Months Ended
	Mar. 31, 2020 shares	May 23, 2018 Vote
Class A Common Stock
Shareholders' Equity
Number of votes per share		1
Exchange basis for newly issued shares | shares	1
Executive Officers | Class C Common Stock
Shareholders' Equity
Number of votes per share		3.5
Blueapple | Class B Common Stock
Shareholders' Equity
Percentage of combined voting power		15.90%
MDP | Current and Former Employees | Class D Common Stock
Shareholders' Equity
Number of votes per share		1