Condensed Consolidated Balance Sheets Parenthetical (USD $)	Mar. 31, 2012	Dec. 31, 2011
Preferred stock, par value per share	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	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	118,213,000	117,675,000
Common stock, shares outstanding	118,213,000	117,675,000
Treasury Stock, Shares	194,000	0