CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Class of Stock [Line Items]
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	149,092,684	146,262,357
Common stock, shares outstanding	149,092,684	146,262,357
Common stock, shares issuable	71,959	71,959
Redeemable convertible cumulative preferred stock, Series A [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized	11	11
Preferred stock, shares issued	6	6
Preferred stock, shares outstanding	6	6
Preferred stock, redemption amount plus accrued dividends	$ 25,000	$ 25,000
Redeemable convertible cumulative preferred stock, Series B [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized	484	484
Preferred stock, shares issued	321	322
Preferred stock, shares outstanding	321	322
Preferred stock, redemption amount plus accrued dividends	$ 2,500	$ 2,500