CONSOLIDATED STATEMENT OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Class A Common Stock
Common stock, par value (USD per share)	$ 0.001	$ 0.001
Class B Common Stock
Common stock, par value (USD per share)	0.001	0.001
Class C Common Stock
Common stock, par value (USD per share)	$ 0.001	$ 0.001