CONSOLIDATED BALANCE SHEET (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounts receivable, allowance (in dollars)	$ 12,437	$ 8,540
Treasury stock, shares	184,182,001us-gaap_TreasuryStockShares	184,945,527us-gaap_TreasuryStockShares
Common stock
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized shares	1,600,000,000	1,600,000,000
Common stock, issued shares	252,170,058	250,982,079
Common stock, outstanding shares	78,356,057	76,404,552
Class B convertible common stock
Common stock, par value (in dollars 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

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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