Condensed consolidated balance sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Accounts receivable, allowance for bad debts	$ 946	$ 399
Class A Common Stock [Member]
Common stock, par value	$ 0.0001
Common stock, shares authorized	300,000,000
Common stock, shares issued	36,598,000
Common stock, shares outstanding	36,598,000
Class B Common Stock [Member]
Common stock, par value	$ 0.0001
Common stock, shares authorized	100,000,000
Common stock, shares issued	62,112,000
Common stock, shares outstanding	62,112,000