CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2017	Dec. 31, 2016
Preferred stock, par value (usd per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, shares outstanding (in shares)	119,556,426
Treasury stock, shares held (in shares)	3,049,257	2,853,433
Class A Common Stock
Common stock, par value (usd per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	75,356,556	33,340,291
Common stock, shares outstanding (in shares)	72,307,299	30,486,858
Class B Common Stock
Common stock, par value (usd per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	47,249,127	88,942,052
Common stock, shares outstanding (in shares)	47,249,127	88,942,052