CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Accounts receivable, allowance	$ 28,837	$ 27,035
Treasury stock - Common stock, Shares	85,974,000	82,924,000
Common Stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, Authorized	1,600,000,000	1,600,000,000
Common stock, Shares issued	222,766,000	220,383,000
Common stock, Shares outstanding	136,793,000	137,459,000
Class B Common Stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, Authorized	400,000,000	400,000,000
Common stock, Shares issued	12,800,000	12,800,000
Common stock, Shares outstanding	12,800,000	12,800,000