Supplemental Detail for Certain Components of Consolidated Balance Sheets (Details 3) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Distributions payable
Declared distributions	$ 47,089	$ 43,675
Noncontrolling interests
Distributions payable
Declared distributions	140	150
Common stock
Distributions payable
Declared distributions	44,692	41,268
Preferred stock
Distributions payable
Declared distributions	$ 2,257	$ 2,257