CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Accounts receivable, related allowances (in dollars)	$ 18,303	$ 19,936
Intangible assets, accumulated amortization (in dollars)	$ 181,227	$ 142,880
Common stock voting, par value (in dollars per share)	$ 0.0025	$ 0.0025
Common stock voting, shares authorized (in shares)	900,000,000	900,000,000
Common stock voting, shares issued (in shares)	255,052,811	254,002,799
Common stock voting, shares outstanding (in shares)	218,873,720	217,574,826
Treasury stock, shares (in shares)	36,179,091	36,427,973