CONSOLIDATED BALANCE SHEET (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounts receivable allowance	$ 16,528	$ 12,437
Treasury Stock, shares	187,137,267	184,182,001
Common Stock
Common Stock, par value (in usd per share)	$ 0.001	$ 0.001
Common Stock, authorized shares	1,600,000,000	1,600,000,000
Common Stock, issued shares	254,014,976	252,170,058
Common Stock, outstanding shares	77,245,709	78,356,057
Class B Convertible Common Stock
Common Stock, par value (in usd per share)	$ 0.001	$ 0.001
Common Stock, authorized shares	400,000,000	400,000,000
Common Stock, issued shares	16,157,499	16,157,499
Common Stock, outstanding shares	5,789,499	5,789,499