CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Allowance for doubtful accounts	$ 713	$ 274
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A Common Stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, share authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	29,014,665	27,213,791
Common stock, shares outstanding	29,014,665	27,213,791
Class B Common Stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, share authorized	500,000,000	500,000,000
Common stock, shares issued	11,933,784	12,426,947
Common stock, shares outstanding	11,933,784	12,426,947