CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Accounts receivable, allowances
Accounts receivable, allowances (in dollars)	$ 2,820	$ 3,782
Common stock
Common stock, par value (in dollars per share)	$ 0.000005	$ 0.000005
Common stock, authorized shares	900,000,000	900,000,000
Common stock, issued shares	0	0
Common stock, outstanding shares	0	0
Preferred stock
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, Authorized shares	100,000,000	100,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Class A Common
Common stock
Common stock, par value (in dollars per share)	$ 0.000005	$ 0.000005
Common stock, authorized shares	750,000,000	750,000,000
Common stock, issued shares	73,379,489	72,271,298
Common stock, outstanding shares	63,729,103	64,786,705
Treasury stock
Treasury stock shares	9,650,386	7,508,985
Class B Common
Common stock
Common stock, par value (in dollars per share)	$ 0.000005	$ 0.000005
Common stock, authorized shares	150,000,000	150,000,000
Common stock, issued shares	82,745,283	83,303,628
Common stock, outstanding shares	82,745,283	83,303,628