Notes Payable and Unsecured Credit Facilities Weighted Average Debt Rates (Details)	Mar. 31, 2016
Mortgages [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	3.696%
Effective Rate [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	1.50%
Effective Rate [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	5.50%
Effective Rate [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	6.10%
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	4.80%
Contractual Rate [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	6.10%