Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity Consolidated Carrying Amounts, Real Estate Assets, net	$ 187,254	$ 211,755
Common stock, shares outstanding	93,219,439	92,258,690
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	93,219,439	92,258,690
Common stock, shares outstanding	93,219,439	92,258,690
Preferred Stock [Member]
Preferred stock, shares authorized	30,000,000	30,000,000
Preferred stock, par value	$ 0.01	$ 0.01
Series G Preferred Stock [Member]
Preferred stock, shares authorized	4,600,000	4,600,000
Preferred units, issued		4,000,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares outstanding		4,000,000
Preferred stock dividend rate (percentage)	6.875%	6.875%
Preferred stock liquidation preference	$ 100,000	$ 100,000
Series H Preferred Stock [Member]
Preferred stock, shares authorized	4,000,000	4,000,000
Preferred units, issued		4,000,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares outstanding		4,000,000
Preferred stock dividend rate (percentage)	6.375%	6.375%
Preferred stock liquidation preference	$ 100,000	$ 100,000