CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Total cash equivalents and marketable securities, securities loaned	$ 4,448,000	$ 4,058,000
Accounts receivable, allowance	$ 235,000	$ 225,000
Convertible preferred stock, par value per share (in dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized	100,000,000	100,000,000
Convertible preferred stock, shares issued	0	0
Convertible preferred stock, shares outstanding	0	0
Common and Capital Stock, Par or Slated Value Per Share	$ 0.001	$ 0.001
Common and Capital Stock, Shares Authorized	15,000,000,000	15,000,000,000
Common and Capital Stock, Value, Issued	$ 686	$ 680
Common and Capital Stock, Shares, Issued	685,490,000	680,172,000
Common and Capital Stock, Shares, Outstanding	685,490,000	680,172,000
Class A Common Stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, number of shares authorized	9,000,000,000	9,000,000,000
Common stock, par value	$ 290	$ 287
Common stock, shares issued	289,834,000	286,560,000
Common stock, shares outstanding	289,834,000	286,560,000
Class B Common Stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, number of shares authorized	3,000,000,000	3,000,000,000
Common stock, par value	$ 52	$ 53
Common stock, shares issued	51,748,000	53,213,000
Common stock, shares outstanding	51,748,000	53,213,000
Class C Capital Stock
Capital stock, par value (in dollars per share)	$ 0.001	$ 0.001
Capital stock, number of shares authorized	3,000,000,000	3,000,000,000
Capital stock, value, issued	$ 344	$ 340
Capital stock, shares issued	343,908,000	340,399,000
Capital stock, shares outstanding	343,908,000	340,399,000