Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Variable Interest Entity Consolidated Carrying Amounts, Real Estate Assets, net	$ 60,575,000	$ 234,532,000
Common stock, par value	$ 0.01
Common Stock [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	82,218,332	82,153,944
Common stock, shares outstanding	82,218,332	82,153,944
Preferred Stock [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	30,000,000	30,000,000
Series G Cumulative Redeemable Preferred Stock
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock dividend rate percentage	6.875%	6.875%
Preferred stock, shares authorized	4,600,000	4,600,000
Preferred stock, shares issued	4,000,000	4,000,000
Preferred stock, shares outstanding	4,000,000	4,000,000
Preferred Stock Liquidation preference	100,000,000	100,000,000
Series H Cumulative Redeemable Preferred Stock
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock dividend rate percentage	6.375%	6.375%
Preferred stock, shares authorized	4,000,000	4,000,000
Preferred stock, shares issued	4,000,000	4,000,000
Preferred stock, shares outstanding	4,000,000	4,000,000
Preferred Stock Liquidation preference	$ 100,000,000	$ 100,000,000