Subsequent Events (Details) (USD $)	1 Months Ended	6 Months Ended
	Jul. 25, 2014 properties Number	Jun. 30, 2014 Number
Subsequent Event [Line Items]
Number of banks in consortium	28	30
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,500,000,000	$ 2,250,000,000
Term Loan	500,000,000
Canadian Denominated Term Loan	250,000,000
Interest Rate margin	1.05%	1.175%
Facility Fee as Percentage of commitment fee	0.20%	0.225%
Line of Credit Facility Maximum Borrowing Capacity Additional	1,000,000,000	1,000,000,000
Available In Alternate Currencies	$ 500,000,000	$ 500,000,000
Term Loan Interest Rate Margin	1.15%
Debt instrument maturity date	Oct. 31, 2018	Mar. 31, 2017