CONSOLIDATED AND COMBINED STATEMENT OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class A Common Stock
Common stock, par value (USD per share)	$ 0.001
Class B Common Stock
Common stock, par value (USD per share)	0.001
Class C Common Stock
Common stock, par value (USD per share)	0.001
Common Stock | Class A Common Stock
Common stock, par value (USD per share)	0.001	$ 0	$ 0
Common Stock | Class B Common Stock
Common stock, par value (USD per share)	0.001	0	0
Common Stock | Class C Common Stock
Common stock, par value (USD per share)	$ 0.001	$ 0	$ 0