Notes Payable and Unsecured Credit Facilities Weighted Average Debt Rates (Details)	Sep. 30, 2016
Effective Rate [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	1.80%
Effective Rate [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	5.30%
Effective Rate [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	6.00%
Effective Rate [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	2.10%
Contractual Rate [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	1.40%
Contractual Rate [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	4.50%
Contractual Rate [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	6.00%
Contractual Rate [Member] | Term Loan [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	2.00%