Equity and Accumulated Other Comprehensive Loss, Net (Forward Equity Sale) (Details) - USD ($) $ in Thousands					12 Months Ended
	May 19, 2017	Sep. 27, 2016	Jun. 02, 2016	May 20, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
New issues of stock during period (in shares/units)					6,111,770
Common stock, shares issued (in shares)					205,470,300	159,019,118
Proceeds from common and preferred stock offerings, net					$ 405,437	$ 1,085,442	$ 918,944
Common Stock
Class of Stock [Line Items]
New issues of stock during period (in shares/units)					2,375,000	12,000,000	10,500,000
Forward Equity Sale
Class of Stock [Line Items]
Common stock subject to forward sale agreements (shares)	2,375,000
Forward Equity Sale | Common Stock
Class of Stock [Line Items]
New issues of stock during period (in shares/units)			14,375,000	12,500,000
New Issues of stock during period, underwriters option (shares)			1,875,000
Common stock, shares issued (in shares)		12,000,000
Proceeds from common and preferred stock offerings, net	$ 200,000	$ 1,100,000