Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Condensed Consolidated Balance Sheets [Abstract]
Allowance for doubtful patient accounts	$ 2,304,813	$ 2,201,875
Preferred stock, par value per share	$ 0.01	$ 0.01
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	95,775,089	92,925,715
Common stock, shares outstanding	94,799,540	91,950,166
Treasury stock, shares	975,549	975,549