CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Statement of Financial Position [Abstract]
Receivables, allowance for doubtful accounts (in dollars)	$ 25,113	$ 20,282
Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, shares authorized	200,000,000	200,000,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized	2,000,000,000	2,000,000,000
Common Stock, shares issued	421,485,862	417,022,853
Common Stock, shares outstanding	421,485,862	417,022,853