Commitments and Contingencies	9 Months Ended
Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments In connection with our development, redevelopment and capital improvement activities, we have entered into various construction-related contracts and we have made commitments to complete certain projects, pursuant to financing or other arrangements. As of September 30, 2015, our commitments related to these capital activities totaled approximately $114.8 million, most of which we expect to incur during the next 12 months. Our commitments related to our One Canal Street development project will be funded in part by a $114.0 million non-recourse property loan, of which $48.5 million was available to draw at September 30, 2015. During the three months ended September 30, 2015, we also entered into a contract to acquire an apartment community currently under construction in Northern California for $320.0 million. Closing of the acquisition is expected to occur upon completion of construction in the summer of 2016. Consistent with our paired-trade discipline, we intend to fund the acquisition on a leverage neutral basis through a ten-year property loan with the balance funded primarily by proceeds from sales of lower-rated apartment communities. We also enter into certain commitments for future purchases of goods and services in connection with the operations of our apartment communities. Those commitments generally have terms of one year or less and reflect expenditure levels comparable to our historical expenditures. Tax Credit Arrangements We are required to manage certain consolidated real estate partnerships in compliance with various laws, regulations and contractual provisions that apply to our historic and low-income housing tax credit syndication arrangements. In some instances, noncompliance with applicable requirements could result in projected tax benefits not being realized and require a refund or reduction of investor capital contributions, which are reported as deferred income in our condensed consolidated balance sheet, until such time as our obligation to deliver tax benefits is relieved. The remaining compliance periods for our tax credit syndication arrangements range from less than one year to 11 years. We do not anticipate that any material refunds or reductions of investor capital contributions will be required in connection with these arrangements. Income Taxes On March 19, 2014, the Internal Revenue Service notified the Aimco Operating Partnership of its intent to audit the 2011 and 2012 tax years. We do not believe the audit will have any material effect on our unrecognized tax benefits, financial condition or results of operations. Legal Matters In addition to the matters described below, we are a party to various legal actions and administrative proceedings arising in the ordinary course of business, some of which are covered by our general liability insurance program, and none of which we expect to have a material adverse effect on our consolidated financial condition, results of operations or cash flows. Limited Partnerships In connection with our acquisitions of interests in real estate partnerships, we are sometimes subject to legal actions, including allegations that such activities may involve breaches of fiduciary duties to the partners of such real estate partnerships or violations of the relevant partnership agreements. We may incur costs in connection with the defense or settlement of such litigation. We believe that we comply with our fiduciary obligations and relevant partnership agreements. Although the outcome of any litigation is uncertain, we do not expect any such legal actions to have a material adverse effect on our consolidated financial condition, results of operations or cash flows. Environmental Various Federal, state and local laws subject apartment community owners or operators to liability for management, and the costs of removal or remediation, of certain potentially hazardous materials that may be present in the land or buildings of an apartment community. Potentially hazardous materials may include polychlorinated biphenyls, petroleum-based fuels, lead-based paint, or asbestos. Such laws often impose liability without regard to fault or whether the owner or operator knew of, or was responsible for, the presence of such materials. The presence of, or the failure to manage or remediate properly, these materials may adversely affect occupancy at such apartment communities as well as the ability to sell or finance such apartment communities. In addition, governmental agencies may bring claims for costs associated with investigation and remediation actions, damages to natural resources and for potential fines or penalties in connection with such damage or with respect to the improper management of hazardous materials. Moreover, private plaintiffs may potentially make claims for personal injury, disease, disability or other infirmities related to the alleged presence of hazardous materials at an apartment community. In addition to potential environmental liabilities or costs associated with our current apartment communities, we may also be responsible for such liabilities or costs associated with communities we acquire or manage in the future, or apartment communities we no longer own or operate. We are engaged in discussions with the Environmental Protection Agency, or EPA, regarding contaminated groundwater in a residential area in the vicinity of an Indiana apartment community that has not been owned by us since 2008. The EPA alleges that we are liable for addressing the contamination in the residential area because a dry cleaner that operated on our former property, prior to our ownership, discharged hazardous materials into the sanitary sewers and the environment. We have undertaken a voluntary remediation of the dry cleaner contamination at our former property under the oversight of the Indiana Department of Environmental Management, or IDEM. However, IDEM has formally terminated us from the voluntary remediation, and we are presently appealing that termination. Based on our review of the scientific data, we believe that the presence of hazardous materials in the separate residential area under review by the EPA is attributable to neighboring property owners (including an auto parts manufacturer), and not the dry cleaner. The EPA is now proposing to list the area on the National Priorities List (i.e., as a Superfund site), which would make the site eligible for additional Federal funding. Were the site to be listed, the EPA could use the funding to further investigate and clean-up the residential area and could then seek to recoup its costs from responsible parties. Although the outcome of this process is uncertain, we do not expect the resolution to have a material adverse effect on our consolidated financial condition, results of operations or cash flows. We also have been contacted by regulators and the current owner of a property in Lake Tahoe regarding environmental issues allegedly stemming from the historic operation of a dry cleaner on the site. An entity owned by us was the former general partner of a now-dissolved company that previously owned the dry cleaner site. The Lahontan Regional Water Quality Control Board, or Board, recently tested domestic wells in the area and found two wells with contaminants linked to dry cleaning. We entered into an agreement with the Board and the current owner to pay for an alternative water connection at an insignificant cost. During the three months ended September 30, 2015, the Board sent us and the current owner a proposed cleanup and abatement order that, if entered, would require us and the current owner to perform additional groundwater investigation and corrective actions. We are currently assessing potential legal and technical grounds for challenging and/or narrowing the scope of the proposed order. Although the outcome of this process is uncertain, we do not expect the resolution to have a material adverse effect on our consolidated financial condition, results of operations or cash flows. We have determined that our legal obligations to remove or remediate certain potentially hazardous materials may be conditional asset retirement obligations, as defined in GAAP. Except in limited circumstances where the asset retirement activities are expected to be performed in connection with a planned construction project or apartment community casualty, we believe that the fair value of our asset retirement obligations cannot be reasonably estimated due to significant uncertainties in the timing and manner of settlement of those obligations. Asset retirement obligations that are reasonably estimable as of September 30, 2015, are immaterial to our consolidated financial condition, results of operations and cash flows.

Commitments and Contingencies

Commitments

In connection with our development, redevelopment and capital improvement activities, we have entered into various construction-related contracts and we have made commitments to complete certain projects, pursuant to financing or other arrangements. As of September 30, 2015, our commitments related to these capital activities totaled approximately $114.8 million, most of which we expect to incur during the next 12 months. Our commitments related to our One Canal Street development project will be funded in part by a $114.0 million non-recourse property loan, of which $48.5 million was available to draw at September 30, 2015.

During the three months ended September 30, 2015, we also entered into a contract to acquire an apartment community currently under construction in Northern California for $320.0 million. Closing of the acquisition is expected to occur upon completion of construction in the summer of 2016. Consistent with our paired-trade discipline, we intend to fund the acquisition on a leverage neutral basis through a ten-year property loan with the balance funded primarily by proceeds from sales of lower-rated apartment communities.

We also enter into certain commitments for future purchases of goods and services in connection with the operations of our apartment communities. Those commitments generally have terms of one year or less and reflect expenditure levels comparable to our historical expenditures.

Tax Credit Arrangements

We are required to manage certain consolidated real estate partnerships in compliance with various laws, regulations and contractual provisions that apply to our historic and low-income housing tax credit syndication arrangements. In some instances, noncompliance with applicable requirements could result in projected tax benefits not being realized and require a refund or reduction of investor capital contributions, which are reported as deferred income in our condensed consolidated balance sheet, until such time as our obligation to deliver tax benefits is relieved. The remaining compliance periods for our tax credit syndication arrangements range from less than one year to 11 years. We do not anticipate that any material refunds or reductions of investor capital contributions will be required in connection with these arrangements.

Income Taxes

On March 19, 2014, the Internal Revenue Service notified the Aimco Operating Partnership of its intent to audit the 2011 and 2012 tax years. We do not believe the audit will have any material effect on our unrecognized tax benefits, financial condition or results of operations.

Legal Matters

In addition to the matters described below, we are a party to various legal actions and administrative proceedings arising in the ordinary course of business, some of which are covered by our general liability insurance program, and none of which we expect to have a material adverse effect on our consolidated financial condition, results of operations or cash flows.

Limited Partnerships

In connection with our acquisitions of interests in real estate partnerships, we are sometimes subject to legal actions, including allegations that such activities may involve breaches of fiduciary duties to the partners of such real estate partnerships or violations of the relevant partnership agreements. We may incur costs in connection with the defense or settlement of such litigation. We believe that we comply with our fiduciary obligations and relevant partnership agreements. Although the outcome of any litigation is uncertain, we do not expect any such legal actions to have a material adverse effect on our consolidated financial condition, results of operations or cash flows.

Environmental

Various Federal, state and local laws subject apartment community owners or operators to liability for management, and the costs of removal or remediation, of certain potentially hazardous materials that may be present in the land or buildings of an apartment community. Potentially hazardous materials may include polychlorinated biphenyls, petroleum-based fuels, lead-based paint, or asbestos. Such laws often impose liability without regard to fault or whether the owner or operator knew of, or was responsible for, the presence of such materials. The presence of, or the failure to manage or remediate properly, these materials may adversely affect occupancy at such apartment communities as well as the ability to sell or finance such apartment communities. In addition, governmental agencies may bring claims for costs associated with investigation and remediation actions, damages to natural resources and for potential fines or penalties in connection with such damage or with respect to the improper management of hazardous materials. Moreover, private plaintiffs may potentially make claims for personal injury, disease, disability or other infirmities related to the alleged presence of hazardous materials at an apartment community. In addition to potential environmental liabilities or costs associated with our current apartment communities, we may also be responsible for such liabilities or costs associated with communities we acquire or manage in the future, or apartment communities we no longer own or operate.

We are engaged in discussions with the Environmental Protection Agency, or EPA, regarding contaminated groundwater in a residential area in the vicinity of an Indiana apartment community that has not been owned by us since 2008. The EPA alleges that we are liable for addressing the contamination in the residential area because a dry cleaner that operated on our former property, prior to our ownership, discharged hazardous materials into the sanitary sewers and the environment. We have undertaken a voluntary remediation of the dry cleaner contamination at our former property under the oversight of the Indiana Department of Environmental Management, or IDEM. However, IDEM has formally terminated us from the voluntary remediation, and we are presently appealing that termination. Based on our review of the scientific data, we believe that the presence of hazardous materials in the separate residential area under review by the EPA is attributable to neighboring property owners (including an auto parts manufacturer), and not the dry cleaner. The EPA is now proposing to list the area on the National Priorities List (i.e., as a Superfund site), which would make the site eligible for additional Federal funding. Were the site to be listed, the EPA could use the funding to further investigate and clean-up the residential area and could then seek to recoup its costs from responsible parties. Although the outcome of this process is uncertain, we do not expect the resolution to have a material adverse effect on our consolidated financial condition, results of operations or cash flows.

We also have been contacted by regulators and the current owner of a property in Lake Tahoe regarding environmental issues allegedly stemming from the historic operation of a dry cleaner on the site. An entity owned by us was the former general partner of a now-dissolved company that previously owned the dry cleaner site. The Lahontan Regional Water Quality Control Board, or Board, recently tested domestic wells in the area and found two wells with contaminants linked to dry cleaning. We entered into an agreement with the Board and the current owner to pay for an alternative water connection at an insignificant cost. During the three months ended September 30, 2015, the Board sent us and the current owner a proposed cleanup and abatement order that, if entered, would require us and the current owner to perform additional groundwater investigation and corrective actions. We are currently assessing potential legal and technical grounds for challenging and/or narrowing the scope of the proposed order. Although the outcome of this process is uncertain, we do not expect the resolution to have a material adverse effect on our consolidated financial condition, results of operations or cash flows.

We have determined that our legal obligations to remove or remediate certain potentially hazardous materials may be conditional asset retirement obligations, as defined in GAAP. Except in limited circumstances where the asset retirement activities are expected to be performed in connection with a planned construction project or apartment community casualty, we believe that the fair value of our asset retirement obligations cannot be reasonably estimated due to significant uncertainties in the timing and manner of settlement of those obligations. Asset retirement obligations that are reasonably estimable as of September 30, 2015, are immaterial to our consolidated financial condition, results of operations and cash flows.