CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowances (in dollars)	$ 25,979	$ 18,855
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	575,000,000	575,000,000
Common stock, shares issued	493,483,403	487,381,255
Common stock, treasury	60,435,257	49,889,078