Commitments and Contingencies (Details Textual) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Commitments related to development, redevelopment and capital improvement activities [Member]
Long-term Purchase Commitment [Line Items]
Commitments related to capital spending activities	$ 184.7
Time Period of Long-term Purchase Commitment	12 months
Maximum [Member] | Commitments related to operations [Member]
Long-term Purchase Commitment [Line Items]
Time Period of Long-term Purchase Commitment	1 year