CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) (USD $)	12 Months Ended										0 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 7.875% Series A Cumulative Redeemable Preferred Stock	Dec. 31, 2012 7.875% Series A Cumulative Redeemable Preferred Stock	Dec. 31, 2011 7.875% Series A Cumulative Redeemable Preferred Stock	Dec. 31, 2013 7.625% Series C Cumulative Redeemable Preferred Stock	Dec. 31, 2012 7.625% Series C Cumulative Redeemable Preferred Stock	Dec. 31, 2013 7.50% Series D Cumulative Redeemable Preferred Stock	Dec. 31, 2012 7.50% Series D Cumulative Redeemable Preferred Stock	Jan. 03, 2012 6.00% Series B Cumulative Convertible Preferred Stock	Dec. 31, 2012 6.00% Series B Cumulative Convertible Preferred Stock	Dec. 31, 2011 6.00% Series B Cumulative Convertible Preferred Stock
Preferred series dividends declared, per share				$ 1.97	$ 1.97	$ 1.97	$ 1.91	$ 1.19	$ 1.88	$ 0.56	$ 1.50	$ 0.375	$ 1.50
Dividends Declared Per Share of Common Stock	$ 1.50	$ 2.05	$ 2.44