Debt (Tables)

3 Months Ended

Mar. 31, 2016

Debt Disclosure [Abstract]

Schedule of Debt [Table Text Block]

(Amounts in thousands)			Interest Rate at		Balance at
			March 31, 2016		March 31, 2016		December 31, 2015
Mortgages Payable:
	Fixed rate			4.04%	$	6,695,401	$	6,356,634
	Variable rate			2.25%		3,259,067		3,258,204
		Total		3.46%		9,954,468		9,614,838
	Deferred financing costs, net and other					(110,226)		(101,125)
		Total, net			$	9,844,242	$	9,513,713
Unsecured Debt:
	Senior unsecured notes			3.68%	$	850,000	$	850,000
	Deferred financing costs, net and other					(5,486)		(5,841)
		Senior unsecured notes, net				844,514		844,159
	Unsecured term loan			1.58%		375,000		187,500
	Deferred financing costs, net and other					(3,924)		(4,362)
		Unsecured term loan, net				371,076		183,138
	Unsecured revolving credit facilities			-		-		550,000
		Total, net			$	1,215,590	$	1,577,297