Commitments and Contingencies (Details Textual) $ in Millions	6 Months Ended
	Jun. 30, 2017 USD ($)
Commitments related to development, redevelopment and capital improvement activities [Member]
Long-term Purchase Commitment [Line Items]
Commitments related to capital spending activities	$ 80.8
Time Period of Long-term Purchase Commitment	12 months
Minimum [Member]
Long-term Purchase Commitment [Line Items]
Compliance Period For Low Income Housing Tax Credit Syndication Agreements	1 year
Maximum [Member]
Long-term Purchase Commitment [Line Items]
Compliance Period For Low Income Housing Tax Credit Syndication Agreements	8 years
Maximum [Member] | Commitments related to operations [Member]
Long-term Purchase Commitment [Line Items]
Time Period of Long-term Purchase Commitment	1 year