Commitments and Contingencies	3 Months Ended
Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments and Contingencies As of March 31, 2019 and December 31, 2018, we participated in two real estate ventures structured as DownREIT partnerships. We have operating and financial control over these ventures and consolidate them in our condensed consolidated financial statements. These ventures allow the outside limited partners to put their interest in the partnership to us, and we have the option to redeem the interest in cash or a fixed number of our common shares, at our discretion. We also participate in a real estate venture that has a property in Texas that allows its outside partner to put operating partnership units to us. We have the option to redeem these units in cash or a fixed number of our common shares, at our discretion. The aggregate redemption value of these interests was approximately $42 million and $36 million as of March 31, 2019 and December 31, 2018, respectively. As of March 31, 2019, we have entered into commitments aggregating $163.6 million comprised principally of construction contracts which are generally due in 12 to 36 months. We issue letters of intent signifying a willingness to negotiate for acquisitions, dispositions or joint ventures, as well as other types of potential transactions, during the ordinary course of our business. Such letters of intent and other arrangements are non-binding to all parties unless and until a definitive contract is entered into by the parties. Even if definitive contracts relating to the acquisition or disposition of property are entered into, these contracts generally provide the purchaser a time period to evaluate the property and conduct due diligence. The purchaser, during this time, will have the ability to terminate a contract without penalty or forfeiture of any deposit or earnest money. No assurance can be provided that any definitive contracts will be entered into with respect to any matter covered by letters of intent, or that we will consummate any transaction contemplated by a definitive contract. Additionally, due diligence periods for property transactions are frequently extended as needed. An acquisition or disposition of property becomes probable at the time the due diligence period expires and the definitive contract has not been terminated. Our risk is then generally extended only to any earnest money deposits associated with property acquisition contracts, and our obligation to sell under a property sales contract. We are subject to numerous federal, state and local environmental laws, ordinances and regulations in the areas where we own or operate properties. We are not aware of any contamination which may have been caused by us or any of our tenants that would have a material effect on our condensed consolidated financial statements. As part of our risk management activities, we have applied and been accepted into state sponsored environmental programs which will limit our expenses if contaminants need to be remediated. We also have an environmental insurance policy that covers us against third party liabilities and remediation costs. While we believe that we do not have any material exposure to environmental remediation costs, changes in the law or new discoveries of contamination may result in additional liabilities to us. Litigation We are involved in various matters of litigation arising in the normal course of business. While we are unable to predict the amounts involved, our management and counsel are of the opinion that, when such litigation is resolved, any additional liability, if any, will not have a material effect on our condensed consolidated financial statements.

Commitments and Contingencies

As of March 31, 2019 and December 31, 2018, we participated in two real estate ventures structured as DownREIT partnerships. We have operating and financial control over these ventures and consolidate them in our condensed consolidated financial statements. These ventures allow the outside limited partners to put their interest in the partnership to us, and we have the option to redeem the interest in cash or a fixed number of our common shares, at our discretion. We also participate in a real estate venture that has a property in Texas that allows its outside partner to put operating partnership units to us. We have the option to redeem these units in cash or a fixed number of our common shares, at our discretion. The aggregate redemption value of these interests was approximately $42 million and $36 million as of March 31, 2019 and December 31, 2018, respectively.

As of March 31, 2019, we have entered into commitments aggregating $163.6 million comprised principally of construction contracts which are generally due in 12 to 36 months.

We issue letters of intent signifying a willingness to negotiate for acquisitions, dispositions or joint ventures, as well as other types of potential transactions, during the ordinary course of our business. Such letters of intent and other arrangements are non-binding to all parties unless and until a definitive contract is entered into by the parties. Even if definitive contracts relating to the acquisition or disposition of property are entered into, these contracts generally provide the purchaser a time period to evaluate the property and conduct due diligence. The purchaser, during this time, will have the ability to terminate a contract without penalty or forfeiture of any deposit or earnest money. No assurance can be provided that any definitive contracts will be entered into with respect to any matter covered by letters of intent, or that we will consummate any transaction contemplated by a definitive contract. Additionally, due diligence periods for property transactions are frequently extended as needed. An acquisition or disposition of property becomes probable at the time the due diligence period expires and the definitive contract has not been terminated. Our risk is then generally extended only to any earnest money deposits associated with property acquisition contracts, and our obligation to sell under a property sales contract.

We are subject to numerous federal, state and local environmental laws, ordinances and regulations in the areas where we own or operate properties. We are not aware of any contamination which may have been caused by us or any of our tenants that would have a material effect on our condensed consolidated financial statements.

As part of our risk management activities, we have applied and been accepted into state sponsored environmental programs which will limit our expenses if contaminants need to be remediated. We also have an environmental insurance policy that covers us against third party liabilities and remediation costs.

While we believe that we do not have any material exposure to environmental remediation costs, changes in the law or new discoveries of contamination may result in additional liabilities to us.

Litigation

We are involved in various matters of litigation arising in the normal course of business. While we are unable to predict the amounts involved, our management and counsel are of the opinion that, when such litigation is resolved, any additional liability, if any, will not have a material effect on our condensed consolidated financial statements.