Accounting for the Impairment of Long-Lived Assets and Fee Development Contracts	6 Months Ended
Jun. 30, 2017
Property, Plant and Equipment [Abstract]
Asset Impairment Charges [Text Block]	Accounting for the Impairment of Long-Lived Assets and Fee Development Contracts Asset Impairment The Company disposes of and anticipates the potential disposition of certain properties prior to the end of their remaining useful lives. There were no impairments recognized during the three or six months ended June 30, 2017 or 2016. The Company has applied reasonable estimates and judgments in evaluating each of its properties and land held for development and has determined that there were no valuation adjustments necessary at June 30, 2017. Should external or internal circumstances change requiring the need to shorten the holding periods or adjust the estimated future cash flows of the Company’s assets, the Company could be required to record impairment charges in the future. Fee Development Contracts From time to time, the Company enters into contracts to develop properties on a fee basis for joint ventures in which the Company holds an interest or for unrelated third parties. In these cases the Company typically agrees to be responsible for all aspects of the development of the project (and, in certain instances, related infrastructure) and to guarantee the timely lien-free completion of construction of the project and the payment, subject to certain exceptions, of cost overruns incurred in the development of the project. If the Company encounters construction delays or unexpected costs in the development of these projects or is otherwise unable to recover the costs it incurs, the resulting unrecovered costs and potential payments to customers could generate losses that would adversely affect the Company's cash flow and net income. On a quarterly basis, the Company applies reasonable estimates and judgments to assess whether or not it is necessary to accrue any estimated future losses with respect to such contracts. There were no such losses recognized during the three or six months ended June 30, 2017 or 2016. Should external or internal circumstances change requiring the Company to adjust the estimated future cash flows from these development contracts or that suggest that such development contracts may result in a loss, the Company could be required to record losses in the future.

Accounting for the Impairment of Long-Lived Assets and Fee Development Contracts

Asset Impairment

The Company disposes of and anticipates the potential disposition of certain properties prior to the end of their remaining useful lives. There were no impairments recognized during the three or six months ended June 30, 2017 or 2016. The Company has applied reasonable estimates and judgments in evaluating each of its properties and land held for development and has determined that there were no valuation adjustments necessary at June 30, 2017. Should external or internal circumstances change requiring the need to shorten the holding periods or adjust the estimated future cash flows of the Company’s assets, the Company could be required to record impairment charges in the future.

Fee Development Contracts

From time to time, the Company enters into contracts to develop properties on a fee basis for joint ventures in which the Company holds an interest or for unrelated third parties. In these cases the Company typically agrees to be responsible for all aspects of the development of the project (and, in certain instances, related infrastructure) and to guarantee the timely lien-free completion of construction of the project and the payment, subject to certain exceptions, of cost overruns incurred in the development of the project. If the Company encounters construction delays or unexpected costs in the development of these projects or is otherwise unable to recover the costs it incurs, the resulting unrecovered costs and potential payments to customers could generate losses that would adversely affect the Company's cash flow and net income. On a quarterly basis, the Company applies reasonable estimates and judgments to assess whether or not it is necessary to accrue any estimated future losses with respect to such contracts. There were no such losses recognized during the three or six months ended June 30, 2017 or 2016. Should external or internal circumstances change requiring the Company to adjust the estimated future cash flows from these development contracts or that suggest that such development contracts may result in a loss, the Company could be required to record losses in the future.