Condensed Consolidated Balance Sheet (Parenthetical) (USD $) In Thousands, except Share data	Sep. 30, 2011	Dec. 31, 2010
Allowance for doubtful accounts	$ 11,211	$ 14,636
Property and Equipment, accumulated depreciation	$ 290,720	$ 281,651
Preferred Stock, shares issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares issued	211,979,262	212,047,774
Common stock, shares outstanding	211,979,262	212,047,774