Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Common stock, shares outstanding	119,425,957
Preferred stock, par value (usd per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Treasury stock, shares held	2,853,433	934,434
Common Class A [Member]
Common stock, par value (usd per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	33,269,086	33,158,855
Common stock, shares outstanding	30,415,653	32,224,421
Common Class B [Member]
Common stock, par value (usd per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	89,010,304	89,108,569
Common stock, shares outstanding	89,010,304	89,108,569