CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Preferred stock, Series C Cumulative Convertible Redeemable Preferred Stock, par value (in dollars per share)		$ 0.01
Preferred stock, Series C Cumulative Convertible Redeemable Preferred Stock, shares authorized (in shares)	4,102,564	4,102,564
Preferred stock, Series C Cumulative Convertible Redeemable Preferred Stock, shares issued (in shares)	0	4,102,564
Preferred stock, Series C Cumulative Convertible Redeemable Preferred Stock, shares outstanding (in shares)	0	4,102,564
Preferred stock, Series C Cumulative Convertible Redeemable Preferred Stock, liquidation preference (in dollars per share)		$ 24.375
Preferred stock, 8.0% Cumulative Redeemable Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, 8.0% Cumulative Redeemable Preferred Stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	160,855,950	135,237,438
Common stock, shares outstanding (in shares)	160,855,950	135,237,438