Aimco Properties 10-Q2 Nov 182018 Q3 Quarterly reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2018	Nov. 01, 2018
Entity Registrant Name	APARTMENT INVESTMENT & MANAGEMENT CO
Entity Central Index Key	922,864
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company
Entity Small Business
Entity Common Stock, Shares Outstanding		155,644,246
AIMCO Properties, LP [Member]
Entity Registrant Name	AIMCO PROPERTIES LP
Entity Central Index Key	926,660
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		164,665,715

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
ASSETS
Total assets	$ 6,185,021	$ 6,079,040
LIABILITIES AND EQUITY
Total liabilities	3,889,571	4,321,750
Preferred noncontrolling interests/Redeemable Preferred Units	101,320	101,537
Commitments and contingencies (Note 4)
Equity/Partners' Capital:
Perpetual Preferred Stock	125,000	125,000
Common Stock, $0.01 par value, 500,787,260 shares authorized, 157,352,109 and 157,189,447 shares issued/outstanding at September 30, 2018 and December 31, 2017, respectively	1,574	1,572
Additional paid-in capital	3,888,312	3,900,042
Accumulated other comprehensive income	4,850	3,603
Distributions in excess of earnings	(1,894,054)	(2,367,073)
Total Aimco equity	2,125,682	1,663,144
Noncontrolling interests in consolidated real estate partnerships	(1,605)	(1,716)
Common noncontrolling interests in Aimco Operating Partnership	70,053	(5,675)
Total equity	2,194,130	1,655,753
Total liabilities and equity	6,185,021	6,079,040
Asset Management [Member]
ASSETS
Net real estate	0	224,873
Cash and cash equivalents	0	16,288
Restricted cash	0	30,928
Other assets	0	15,533
LIABILITIES AND EQUITY
Non-recourse property debt, net	0	227,141
Accrued liabilities and other	0	19,812
Aimco Real Estate [Member]
ASSETS
Buildings and improvements	6,503,956	6,174,149
Land	1,765,678	1,753,604
Total real estate	8,269,634	7,927,753
Accumulated depreciation	(2,538,979)	(2,522,358)
Net real estate	5,730,655	5,405,395
Cash and cash equivalents	58,032	60,498
Restricted cash	46,267	34,827
Other assets	350,067	272,739
Assets held for sale	0	17,959
LIABILITIES AND EQUITY
Non-recourse property debt, net	3,646,789	3,545,109
Term loan, net	0	249,501
Revolving credit facility borrowings	0	67,160
Total indebtedness associated with Real Estate portfolio	3,646,789	3,861,770
Accrued liabilities and other	242,782	213,027
AIMCO Properties, LP [Member]
ASSETS
Total assets	6,185,021	6,079,040
LIABILITIES AND EQUITY
Total liabilities	3,889,571	4,321,750
Preferred noncontrolling interests/Redeemable Preferred Units	101,320	101,537
Commitments and contingencies (Note 4)
Equity/Partners' Capital:
Preferred units	125,000	125,000
General Partner and Special Limited Partner	2,000,682	1,538,144
Limited Partners	70,053	(5,675)
Partners’ capital attributable to the Aimco Operating Partnership	2,195,735	1,657,469
Noncontrolling interests in consolidated real estate partnerships	(1,605)	(1,716)
Total partners’ capital	2,194,130	1,655,753
Total liabilities and equity	6,185,021	6,079,040
AIMCO Properties, LP [Member] \| Asset Management [Member]
ASSETS
Net real estate	0	224,873
Cash and cash equivalents	0	16,288
Restricted cash	0	30,928
Other assets	0	15,533
LIABILITIES AND EQUITY
Non-recourse property debt, net	0	227,141
Accrued liabilities and other	0	19,812
AIMCO Properties, LP [Member] \| Aimco Real Estate [Member]
ASSETS
Buildings and improvements	6,503,956	6,174,149
Land	1,765,678	1,753,604
Total real estate	8,269,634	7,927,753
Accumulated depreciation	(2,538,979)	(2,522,358)
Net real estate	5,730,655	5,405,395
Cash and cash equivalents	58,032	60,498
Restricted cash	46,267	34,827
Other assets	350,067	272,739
Assets held for sale	0	17,959
LIABILITIES AND EQUITY
Non-recourse property debt, net	3,646,789	3,545,109
Term loan, net	0	249,501
Revolving credit facility borrowings	0	67,160
Total indebtedness associated with Real Estate portfolio	3,646,789	3,861,770
Accrued liabilities and other	$ 242,782	$ 213,027

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized (in shares)	500,787,260	500,787,260
Common Stock, shares issued (in shares)	157,352,109	157,189,447
Common Stock, shares outstanding (in shares)	157,352,109	157,189,447

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
REVENUES
Tax credit and transaction revenues	$ 3,411	$ 2,695	$ 6,987	$ 8,242
Total revenues	242,481	254,635	740,388	750,208
OPERATING EXPENSES
Depreciation and amortization	96,406	92,513	286,439	268,836
General and administrative expenses	12,479	10,529	37,196	31,599
Other expenses, net	5,780	2,272	13,624	6,661
Total operating expenses	195,527	195,430	590,696	573,508
Operating income	46,954	59,205	149,692	176,700
Interest income	2,712	2,047	7,768	6,251
Interest expense	(45,492)	(50,682)	(143,193)	(145,422)
Other, net	(283)	6,937	141	7,602
Income before income taxes and gain (loss) on dispositions	3,891	17,507	14,408	45,131
Income tax benefit	27,941	4,870	69,724	14,878
Income before gain (loss) on dispositions	31,832	22,377	84,132	60,009
Gain (loss) on dispositions of real estate and the Asset Management business, inclusive of related income tax	572,085	(233)	622,631	881
Net income	603,917	22,144	706,763	60,890
Noncontrolling interests:
Net (income) loss attributable to noncontrolling interests in consolidated real estate partnerships	(1,794)	249	(8,045)	(1,515)
Net income attributable to preferred noncontrolling interests in Aimco Operating Partnership	(1,934)	(1,938)	(5,805)	(5,826)
Net income attributable to common noncontrolling interests in Aimco Operating Partnership	(30,198)	(820)	(34,093)	(2,164)
Net income attributable to noncontrolling interests	(33,926)	(2,509)	(47,943)	(9,505)
Net income attributable to the company	569,991	19,635	658,820	51,385
Net income attributable to the company's preferred equity holders	(2,148)	(2,148)	(6,445)	(6,445)
Net income attributable to participating securities	(814)	(57)	(1,004)	(176)
Net income attributable to the company's common equity holders	$ 567,029	$ 17,430	$ 651,371	$ 44,764
Earnings attributable to the company per common share/unit
Net income attributable to the company per common share/unit - basic (in dollars per share/unit)	$ 3.62	$ 0.11	$ 4.16	$ 0.29
Net income attributable to the company per common share/unit - diluted (in dollars per share/unit)	3.61	0.11	4.15	0.29
Dividends declared per common share/unit	$ 0.38	$ 0.36	$ 1.14	$ 1.08
Weighted average number of shares outstanding - basic	156,711	156,306	156,674	156,290
Weighted average number of shares outstanding - diluted	156,938	156,835	156,836	156,768
Asset Management [Member]
REVENUES
Rental and other property revenues	$ 5,022	$ 18,232	$ 42,830	$ 55,327
OPERATING EXPENSES
Property operating expenses	2,608	8,872	20,865	26,458
Aimco Real Estate [Member]
REVENUES
Rental and other property revenues	234,048	233,708	690,571	686,639
OPERATING EXPENSES
Property operating expenses	78,254	81,244	232,572	239,954
AIMCO Properties, LP [Member]
REVENUES
Tax credit and transaction revenues	3,411	2,695	6,987	8,242
Total revenues	242,481	254,635	740,388	750,208
OPERATING EXPENSES
Depreciation and amortization	96,406	92,513	286,439	268,836
General and administrative expenses	12,479	10,529	37,196	31,599
Other expenses, net	5,780	2,272	13,624	6,661
Total operating expenses	195,527	195,430	590,696	573,508
Operating income	46,954	59,205	149,692	176,700
Interest income	2,712	2,047	7,768	6,251
Interest expense	(45,492)	(50,682)	(143,193)	(145,422)
Other, net	(283)	6,937	141	7,602
Income before income taxes and gain (loss) on dispositions	3,891	17,507	14,408	45,131
Income tax benefit	27,941	4,870	69,724	14,878
Income before gain (loss) on dispositions	31,832	22,377	84,132	60,009
Gain (loss) on dispositions of real estate and the Asset Management business, inclusive of related income tax	572,085	(233)	622,631	881
Net income	603,917	22,144	706,763	60,890
Noncontrolling interests:
Net (income) loss attributable to noncontrolling interests in consolidated real estate partnerships	(1,794)	249	(8,045)	(1,515)
Net income attributable to the company	602,123	22,393	698,718	59,375
Net income attributable to the company's preferred equity holders	(4,082)	(4,086)	(12,250)	(12,271)
Net income attributable to participating securities	(941)	(61)	(1,145)	(184)
Net income attributable to the company's common equity holders	$ 597,100	$ 18,246	$ 685,323	$ 46,920
Earnings attributable to the company per common share/unit
Net income attributable to the company per common share/unit - basic (in dollars per share/unit)	$ 3.62	$ 0.11	$ 4.17	$ 0.29
Net income attributable to the company per common share/unit - diluted (in dollars per share/unit)	3.61	0.11	4.16	0.29
Dividends declared per common share/unit	$ 0.38	$ 0.36	$ 1.14	$ 1.08
Weighted average number of shares outstanding - basic	165,081	163,664	164,493	163,739
Weighted average number of shares outstanding - diluted	165,326	164,194	164,654	164,218
AIMCO Properties, LP [Member] \| Asset Management [Member]
REVENUES
Rental and other property revenues	$ 5,022	$ 18,232	$ 42,830	$ 55,327
OPERATING EXPENSES
Property operating expenses	2,608	8,872	20,865	26,458
AIMCO Properties, LP [Member] \| Aimco Real Estate [Member]
REVENUES
Rental and other property revenues	234,048	233,708	690,571	686,639
OPERATING EXPENSES
Property operating expenses	$ 78,254	$ 81,244	$ 232,572	$ 239,954

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net income	$ 603,917	$ 22,144	$ 706,763	$ 60,890
Other comprehensive gain:
Realized and unrealized gains (losses) on interest rate swaps	0	75	0	(280)
Losses on interest rate swaps reclassified into earnings from accumulated other comprehensive loss	757	594	1,391	1,349
Unrealized gains (losses) on available for sale debt securities	979	381	(72)	(40)
Other comprehensive gain	1,736	1,050	1,319	1,029
Comprehensive income	605,653	23,194	708,082	61,919
Comprehensive income attributable to noncontrolling interests	(34,020)	(2,557)	(48,015)	(9,647)
Comprehensive income attributable to Aimco/Operating Partnership	571,633	20,637	660,067	52,272
AIMCO Properties, LP [Member]
Net income	603,917	22,144	706,763	60,890
Other comprehensive gain:
Realized and unrealized gains (losses) on interest rate swaps	0	75	0	(280)
Losses on interest rate swaps reclassified into earnings from accumulated other comprehensive loss	757	594	1,391	1,349
Unrealized gains (losses) on available for sale debt securities	979	381	(72)	(40)
Other comprehensive gain	1,736	1,050	1,319	1,029
Comprehensive income	605,653	23,194	708,082	61,919
Comprehensive income attributable to noncontrolling interests	(1,794)	249	(8,045)	(1,616)
Comprehensive income attributable to Aimco/Operating Partnership	$ 603,859	$ 23,443	$ 700,037	$ 60,303

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 706,763	$ 60,890
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	286,439	268,836
Gain (loss) on dispositions of real estate and the Asset Management business, inclusive of related income tax	(622,631)	(881)
Income Tax Expense (Benefit)	(69,724)	(14,878)
Other adjustments	11,762	398
Net changes in operating assets and operating liabilities	(9,683)	(19,216)
Net cash provided by operating activities	302,926	295,149
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of real estate and deposits related to purchases of real estate	(212,358)	(11,706)
Capital expenditures	(253,149)	(266,623)
Proceeds from dispositions of real estate	708,464	10,888
Purchases of corporate assets	(5,530)	(7,358)
Other investing activities	1,695	(1,086)
Net cash provided by (used in) investing activities	239,122	(275,885)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from non-recourse property debt	360,613	165,785
Principal repayments of non-recourse property debt	(403,141)	(250,674)
Proceeds from (Repayments of) Short-term Debt, Maturing in More than Three Months	(250,000)	250,000
Proceeds from (Repayments of) Lines of Credit	(67,160)	338,290
Payment of dividends to holders of preferred securities	(6,445)	(6,445)
Payment of dividends to holders of Common Stock	(178,937)	(168,987)
Payment of distributions to noncontrolling interests	(22,549)	(15,829)
Purchases and redemptions of noncontrolling interests	(12,256)	(324,265)
Other financing activities	415	4,693
Net cash used in financing activities	(580,290)	(16,818)
NET (DECREASE) INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(38,242)	2,446
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT BEGINNING OF PERIOD	142,541	131,150
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT END OF PERIOD	104,299	133,596
AIMCO Properties, LP [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	706,763	60,890
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	286,439	268,836
Gain (loss) on dispositions of real estate and the Asset Management business, inclusive of related income tax	(622,631)	(881)
Income Tax Expense (Benefit)	(69,724)	(14,878)
Other adjustments	11,762	398
Net changes in operating assets and operating liabilities	(9,683)	(19,216)
Net cash provided by operating activities	302,926	295,149
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of real estate and deposits related to purchases of real estate	(212,358)	(11,706)
Capital expenditures	(253,149)	(266,623)
Proceeds from dispositions of real estate	708,464	10,888
Purchases of corporate assets	(5,530)	(7,358)
Other investing activities	1,695	(1,086)
Net cash provided by (used in) investing activities	239,122	(275,885)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from non-recourse property debt	360,613	165,785
Principal repayments of non-recourse property debt	(403,141)	(250,674)
Proceeds from (Repayments of) Short-term Debt, Maturing in More than Three Months	(250,000)	250,000
Proceeds from (Repayments of) Lines of Credit	(67,160)	338,290
Payment of dividends to holders of preferred securities	(12,250)	(12,271)
Payment of distributions to General Partner and Special Limited Partner	(178,937)	(168,987)
Payment of distributions to Limited Partners	(8,810)	(8,026)
Payment of distributions to noncontrolling interests	(7,934)	(1,977)
Purchases and redemptions of noncontrolling interests	(3,581)	(311,079)
Payments to Noncontrolling Interests	(8,675)	(13,187)
Other financing activities	415	4,692
Net cash used in financing activities	(580,290)	(16,818)
NET (DECREASE) INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(38,242)	2,446
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT BEGINNING OF PERIOD	142,541	131,150
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT END OF PERIOD	$ 104,299	$ 133,596

Organization

Organization	9 Months Ended
Organization	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Apartment Investment and Management Company, or Aimco, is a Maryland corporation incorporated on January 10, 1994. Aimco is a self-administered and self-managed real estate investment trust, or REIT. AIMCO Properties, L.P., or the Aimco Operating Partnership, is a Delaware limited partnership formed on May 16, 1994, to conduct our business, which is focused on the ownership, management, redevelopment and limited development of quality apartment communities located in several of the largest markets in the United States. Aimco, through its wholly-owned subsidiaries, AIMCO-GP, Inc. and AIMCO-LP Trust, owns a majority of the ownership interests in the Aimco Operating Partnership. Aimco conducts all of its business and owns all of its assets through the Aimco Operating Partnership. Interests in the Aimco Operating Partnership that are held by limited partners other than Aimco are referred to as OP Units. OP Units include common partnership units, which we refer to as common OP Units, as well as partnership preferred units, which we refer to as preferred OP Units. As of September 30, 2018 , after eliminations for units held by consolidated subsidiaries, the Aimco Operating Partnership had 166,384,727 common partnership units outstanding. As of September 30, 2018 , Aimco owned 157,352,109 of the common partnership units ( 94.6% of the common partnership units) of the Aimco Operating Partnership and Aimco had outstanding an equal number of shares of its Class A Common Stock, which we refer to as Common Stock. Except as the context otherwise requires, “we,” “our” and “us” refer to Aimco, the Aimco Operating Partnership and their consolidated subsidiaries, collectively. As of September 30, 2018 , we owned an equity interest in 133 apartment communities with 36,481 apartment homes in our Real Estate portfolio. Our Real Estate portfolio is diversified by both price point and geography and consists primarily of market rate apartment communities in which we own a substantial interest. We consolidated 129 of these apartment communities with 36,339 apartment homes and these communities comprise our reportable segment.

Significant Transactions, Dispo

Significant Transactions, Dispositions of Apartment Communities and Assets Held for Sale	9 Months Ended
	Sep. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Disposals and Other Significant Transactions	Significant Transactions, Acquisitions and Dispositions of Apartment Communities Acquisition of Apartment Communities During the nine months ended September 30, 2018 , we acquired for $160.0 million Bent Tree Apartments, a 748 -apartment home community in Fairfax County, Virginia. The purchase price, plus $1.0 million of capitalized transaction costs, was allocated as follows: $47.0 million to land; $113.0 million to buildings and improvements; and $1.0 million to other items. During the nine months ended September 30, 2018 , we acquired four apartment communities in the Philadelphia area, including 665 apartment homes and 153,000 square feet of office and retail space. The gross purchase price consisted of $208.9 million of assumed property-level debt and the issuance of 1.2 million OP Units. In accordance with GAAP, the OP Units were valued at $41.08 per unit, the closing price of Aimco’s common share on May 1, 2018. Total consideration, plus $6.4 million of capitalized transaction costs, was allocated as follows: $14.1 million to land; $289.7 million to buildings and improvements; $8.3 million to intangible assets; and $12.3 million to intangible liabilities. In connection with the foregoing, we have also contracted to acquire an additional apartment community in the Philadelphia area, which is expected to be purchased upon completion of the construction in the first half of 2019. Dispositions of Apartment Communities and Assets Held for Sale During the nine months ended September 30, 2018 , we sold four apartment communities with 1,334 apartment homes for a gain on disposition of $173.2 million , net of income tax, and gross proceeds of $242.3 million resulting in $230.1 million in net proceeds to us. Two of these communities are located in southern Virginia, one in suburban Maryland, and one in north Philadelphia. During the nine months ended September 30, 2018 , we sold our interests in the entities owning the La Jolla Cove property in settlement of legal actions filed in 2014 by a group of disappointed buyers who had hoped to acquire the property. We provided seller financing with a stated value of $48.6 million and received net cash proceeds of approximately $5.0 million in the sale. During the nine months ended September 30, 2018 , we sold for $590.0 million our Asset Management business and our four affordable apartment communities located in the Hunters Point area of San Francisco. The sale resulted in a gain of $448.2 million , net of $54.1 million of taxes, and net cash proceeds of $512.2 million after payment of transaction costs and repayment of property-level debt encumbering the Hunters Point apartment communities. In addition to the apartment communities we sold during the periods presented, from time to time we may be marketing for sale certain apartment communities that are inconsistent with our long-term investment strategy. At the end of each reporting period, we evaluate whether such communities meet the criteria to be classified as held for sale. As of September 30, 2018 , no apartment communities were classified as held for sale.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments In connection with our redevelopment, development and capital improvement activities, we have entered into various construction-related contracts and we have made commitments to complete redevelopment and development of certain apartment communities, pursuant to financing or other arrangements. As of September 30, 2018 , our commitments related to these capital activities totaled approximately $130.6 million , most of which we expect to incur during the next 12 months . We 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 For various partnerships served by our Asset Management business prior to its sale, we were required to manage the partnerships and related apartment communities in compliance with various laws, regulations and contractual provisions that apply to 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 by the limited partners in these partnerships and would require a refund or reduction of investor capital contributions for actions taken during our ownership. In connection with the July 25, 2018, sale of our Asset Management business, the performance obligation related to continuing compliance was assumed by the purchaser. Income Taxes In 2014, the Internal Revenue Service initiated an audit of the Aimco Operating Partnership’s 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. 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. 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. Moreover, private plaintiffs may potentially make claims for investigation and remediation costs they incur or for personal injury, disease, disability or other infirmities related to the alleged presence of hazardous materials. 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, and the Indiana Department of Environmental Management, or IDEM, 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 contamination allegedly derives from a dry cleaner that operated on our former property, prior to our ownership. We have undertaken a voluntary remediation of the dry cleaner contamination under IDEM’s oversight, and in previous years accrued our share of the then-estimated cleanup and abatement costs. In 2016, EPA listed our former community and a number of residential communities in the vicinity on the National Priorities List, or NPL (i.e. as a Superfund site). In May 2018, we prevailed on our federal judicial appeal vacating the Superfund listing. We continue to work with EPA and IDEM to identify options for clean-up of the site. Although the outcome of these processes are uncertain, we do not expect their 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, California, regarding environmental issues allegedly stemming from the historic operation of a dry cleaner. An entity owned by us was the former general partner of a now-dissolved partnership that previously owned a site that was used for dry cleaning. That entity and the current property owner have been remediating the dry cleaner site since 2009, under the oversight of the Lahontan Regional Water Quality Control Board, or Lahontan. In May 2017, Lahontan issued a final cleanup and abatement order that names four potentially-responsible parties, acknowledges that there may be additional responsible parties, and requires the named parties to perform additional groundwater investigation and corrective actions with respect to onsite and offsite contamination. We are appealing the final order while simultaneously complying with it. Although the outcome of this process is uncertain, we do not expect its 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, 2018 , are immaterial to our consolidated financial condition, results of operations and cash flows.

Earnings per Share_Unit

Earnings per Share/Unit	9 Months Ended
Earnings per Share/Unit	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings per Share/Unit	Earnings per Share and Unit Aimco and the Aimco Operating Partnership calculate basic earnings per common share and basic earnings per common unit based on the weighted average number of shares of Common Stock and common partnership units and participating securities outstanding, and calculate diluted earnings per share and diluted earnings per unit taking into consideration dilutive common stock and common partnership unit equivalents and dilutive convertible securities outstanding during the period. Our common stock and common partnership unit equivalents include options to purchase shares of Common Stock, which, if exercised, would result in Aimco’s issuance of additional shares and the Aimco Operating Partnership’s issuance to Aimco of additional common partnership units equal to the number of shares purchased under the options. These equivalents also include unvested total stockholder return, or TSR, restricted stock awards that do not meet the definition of participating securities, which would result in an increase in the number of common shares and common partnership units outstanding equal to the number of shares that vest. The dilutive effect of these securities was 0.2 million shares or units for the three and nine months ended September 30, 2018 . The dilutive effect of these securities was 0.5 million shares or units for the three and nine months ended September 30, 2017 . Securities with dilutive effect are included in the denominator for calculating diluted earnings per share and unit during these periods. There were 0.2 million potential shares and 0.2 million potential units not dilutive and excluded from the denominator for calculating diluted earnings per share and per unit, respectively, for both the three and nine months ended September 30, 2018 and 2017 . Our time-based restricted stock awards receive dividends similar to shares of Common Stock and common partnership units prior to vesting and our TSR long-term incentive partnership units receive a percentage of the distributions paid to common partnership units prior to vesting. These dividends and distributions are not forfeited if the awards fail to vest. Therefore, the unvested shares and units related to these awards are participating securities. The effect of participating securities is included in basic and diluted earnings per share and unit computations using the two-class method of allocating distributed and undistributed earnings when the two-class method is more dilutive than the treasury method. There were 0.3 million and 0.2 million unvested participating securities as of September 30, 2018 and 2017 , respectively. The Aimco Operating Partnership has various classes of preferred OP Units, which may be redeemed at the holders’ option. The Aimco Operating Partnership may redeem these units for cash, or at its option, shares of Common Stock. As of September 30, 2018 , these preferred OP Units were potentially redeemable for approximately 2.3 million shares of Common Stock (based on the period end market price), or cash. The Aimco Operating Partnership has a redemption policy that requires cash settlement of redemption requests for the preferred OP Units, subject to limited exceptions. Accordingly, we have excluded these securities from earnings per share and unit computations and we expect to exclude them in future periods.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
Fair Value Measurements	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Recurring Fair Value Measurements We measure at fair value on a recurring basis our investments in the securitization trust that holds certain of our property debt, which we classify as available for sale, or AFS, debt securities, which are classified within Level 2 of the GAAP fair value hierarchy. Our investments in debt securities classified as AFS are presented within other assets in the accompanying condensed consolidated balance sheets. We hold several positions in the securitization trust that pay interest currently and we also hold the first loss position in the securitization trust, which accrues interest over the term of the investment. We are accreting the discount to the $100.9 million face value of the investments into interest income using the effective interest method over the remaining term of the investments, which, as of September 30, 2018 , was approximately 2.7 years. Our amortized cost basis for these investments, which represents the original cost adjusted for interest accretion less interest payments received, was $82.1 million and $77.7 million at September 30, 2018 and December 31, 2017 , respectively. We estimated the fair value of these investments to be $87.0 million and $82.8 million at September 30, 2018 and December 31, 2017 , respectively. We estimate the fair value of these investments using an income and market approach with primarily observable inputs, including yields and other information regarding similar types of investments, and adjusted for certain unobservable inputs specific to these investments. The fair value of the positions that pay interest currently typically moves in an inverse relationship with movements in interest rates. The fair value of the first loss position is primarily correlated to collateral quality and demand for similar subordinate commercial mortgage-backed securities. Prior to the July 2018 sale of our Asset Management business, we consolidated certain partnerships served by our Asset Management business. These partnerships entered into interest rate swap agreements to limit exposure to interest rate risk on the partnerships’ debt by effectively converting the interest from a variable rate to a fixed rate. We estimated the fair value of interest rate swaps as of September 30, 2017, using an income approach with primarily observable inputs, including information regarding the hedged variable cash flows and forward yield curves relating to the variable interest rates on which the hedged cash flows are based. The fair value of these interest rate swaps was classified within Level 2 of the GAAP fair value hierarchy. The following table sets forth a summary of the changes in fair value of these interest rate swaps (in thousands): Nine Months Ended September 30, 2018 2017 Beginning balance $ (1,795 ) $ (3,175 ) Realized losses included in interest expense 404 73 Realized losses on derecognition of interest rate swaps 1,115 273 Losses on interest rate swaps reclassified into interest expense from accumulated other comprehensive loss 276 1,076 Unrealized losses included in equity and partners’ capital — (280 ) Ending balance $ — $ (2,033 ) For the nine months ended September 30, 2018 , realized losses on derecognition of interest rate swaps included in earnings represents previously unrealized losses related to interest rate swaps to which certain partnerships served by our Asset Management business were parties. Upon sale of our Asset Management business, the accumulated other comprehensive income related to the swaps was realized as a component of the gain on disposition. Please refer to Note 3 for further discussion of this transaction. For the nine months ended September 30, 2017 , realized losses on derecognition of interest rate swaps included in earnings represents previously unrealized losses related to an interest rate swap to which the partnership owning the final Napico property was a party, as described in Note 11 to our consolidated financial statements included in Aimco’s and the Aimco Operating Partnership’s combined Annual Report on Form 10-K. Fair Value Disclosures We believe that the carrying values of the consolidated amounts of cash and cash equivalents, receivables and payables approximate their fair values at September 30, 2018 , and December 31, 2017 , due to their relatively short-term nature and high probability of realization. The carrying value of the total indebtedness associated with our Real Estate portfolio approximated its estimated fair value at September 30, 2018 and December 31, 2017 . We estimate the fair value of our consolidated debt using an income and market approach, including comparison of the contractual terms to observable and unobservable inputs such as market interest rate risk spreads, contractual interest rates, remaining periods to maturity, collateral quality and loan to value ratios on similarly encumbered apartment communities within our portfolio. We classify the fair value of debt within Level 3 of the GAAP valuation hierarchy based on the significance of certain of the unobservable inputs used to estimate its fair value.

Business Segments

Business Segments	9 Months Ended
Business Segments	Sep. 30, 2018
Segment Reporting [Abstract]
Business Segments	Business Segments Our chief executive officer, who is our chief operating decision maker, uses proportionate property net operating income to assess the operating performance of our apartment communities. Proportionate property net operating income is defined as our share of rental and other property revenue less our share of property operating expenses, including real estate taxes, for consolidated apartment communities we own and manage. Beginning in 2018, we exclude from rental and other property revenues the amount of utilities cost reimbursed by residents and reflect such amount as a reduction of the related utility expense within property operating expenses in our evaluation of segment results. In our condensed consolidated statements of operations, utility reimbursements are included in rental and other property revenues, in accordance with GAAP. The tables below have been revised to conform to this presentation. Apartment communities are classified as either part of our Real Estate portfolio or, prior to the sale in July 2018, those owned through partnerships served by our Asset Management business. As of September 30, 2018 , for segment performance evaluation, our Real Estate segment included 129 consolidated apartment communities with 36,339 apartment homes and excluded four apartment communities with 142 apartment homes that we neither manage nor consolidate. Prior to the July 2018 sale of our Asset Management business, we consolidated certain partnerships in which we held nominal ownership positions. These partnerships own low-income housing tax credit apartment communities. Neither the results of operations nor the assets of these partnerships and apartment communities were quantitatively material; therefore, we have one reportable segment, Real Estate. The following tables present the revenues, net operating income and income before gain on dispositions of our Real Estate segment on a proportionate basis and excluding amounts related to apartment communities sold as of September 30, 2018 for the three and nine months ended September 30, 2018 and 2017 (in thousands): Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Reportable Segment (2) Consolidated Three months ended September 30, 2018: Rental and other property revenues attributable to Real Estate $ 222,856 $ 8,926 $ 2,266 $ 234,048 Rental and other property revenues of partnerships served by Asset Management business — — 5,022 5,022 Tax credit and transaction revenues — — 3,411 3,411 Total revenues 222,856 8,926 10,699 242,481 Property operating expenses attributable to Real Estate 62,863 8,405 6,986 78,254 Property operating expenses of partnerships served by Asset Management business — — 2,608 2,608 Other operating expenses not allocated to reportable segment (3) — — 114,665 114,665 Total operating expenses 62,863 8,405 124,259 195,527 Operating income 159,993 521 (113,560 ) 46,954 Other items included in income before gain on dispositions (4) — — (15,122 ) (15,122 ) Income before gain on dispositions $ 159,993 $ 521 $ (128,682 ) $ 31,832 Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Reportable Segment (2) Consolidated Three months ended September 30, 2017: Rental and other property revenues attributable to Real Estate $ 203,935 $ 8,155 $ 21,618 $ 233,708 Rental and other property revenues of partnerships served by Asset Management business — — 18,232 18,232 Tax credit and transaction revenues — — 2,695 2,695 Total revenues 203,935 8,155 42,545 254,635 Property operating expenses attributable to Real Estate 57,592 7,609 16,043 81,244 Property operating expenses of partnerships served by Asset Management business — — 8,872 8,872 Other operating expenses not allocated to reportable segment (3) — — 105,314 105,314 Total operating expenses 57,592 7,609 130,229 195,430 Operating income 146,343 546 (87,684 ) 59,205 Other items included in income before gain on dispositions (4) — — (36,828 ) (36,828 ) Income before gain on dispositions $ 146,343 $ 546 $ (124,512 ) $ 22,377 Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Reportable Segment (2) Consolidated Nine months ended September 30, 2018: Rental and other property revenues attributable to Real Estate $ 643,656 $ 25,903 $ 21,012 $ 690,571 Rental and other property revenues of partnerships served by Asset Management business — — 42,830 42,830 Tax credit and transaction revenues — — 6,987 6,987 Total revenues 643,656 25,903 70,829 740,388 Property operating expenses attributable to Real Estate 183,119 24,337 25,116 232,572 Property operating expenses of partnerships served by Asset Management business — — 20,865 20,865 Other operating expenses not allocated to reportable segment (3) — — 337,259 337,259 Total operating expenses 183,119 24,337 383,240 590,696 Operating income 460,537 1,566 (312,411 ) 149,692 Other items included in income before gain on dispositions (4) — — (65,560 ) (65,560 ) Income before gain on dispositions $ 460,537 $ 1,566 $ (377,971 ) $ 84,132 Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Reportable Segment (2) Consolidated Nine months ended September 30, 2017: Rental and other property revenues attributable to Real Estate $ 589,349 $ 35,542 $ 61,748 $ 686,639 Rental and other property revenues of partnerships served by Asset Management business — — 55,327 55,327 Tax credit and transaction revenues — — 8,242 8,242 Total revenues 589,349 35,542 125,317 750,208 Property operating expenses attributable to Real Estate 169,311 25,505 45,138 239,954 Property operating expenses of partnerships served by Asset Management business — — 26,458 26,458 Other operating expenses not allocated to reportable segment (3) — — 307,096 307,096 Total operating expenses 169,311 25,505 378,692 573,508 Operating income 420,038 10,037 (253,375 ) 176,700 Other items included in income before gain on dispositions (4) — — (116,691 ) (116,691 ) Income before gain on dispositions $ 420,038 $ 10,037 $ (370,066 ) $ 60,009 (1) Represents adjustments for the noncontrolling interests in consolidated real estate partnerships’ share of the results of consolidated apartment communities in our Real Estate segment, which are included in the related consolidated amounts, but excluded from proportionate property net operating income for our segment evaluation. Also includes the reclassification of utility reimbursements from revenues to property operating expenses for the purpose of evaluating segment results. Utility reimbursements are included in rental and other property revenues in our condensed consolidated statements of operations prepared in accordance with GAAP. (2) Includes the operating results of apartment communities sold during the periods shown or held for sale at the end of the period, if any, and the operating results of apartment communities owned by consolidated partnerships served by our Asset Management business prior to its sale in July 2018. Corporate and Amounts Not Allocated to Reportable Segment also includes property management expenses and casualty gains and losses, which are included in consolidated property operating expenses and are not part of our segment performance measure. (3) Other operating expenses not allocated to reportable segment consists of depreciation and amortization, general and administrative expenses and other operating expenses, which are not included in our measure of segment performance. (4) Other items included in income before gain on dispositions primarily consists of interest and income tax benefit. The assets of our reportable segment and the consolidated assets not allocated to our segment are as follows (in thousands): September 30, 2018 December 31, 2017 Real Estate $ 5,861,647 $ 5,391,816 Corporate and other assets (1) 323,374 687,224 Total consolidated assets $ 6,185,021 $ 6,079,040 (1) Includes the assets not allocated to our reportable segment, primarily corporate assets, and as of December 31, 2017 , assets of apartment communities and the Asset Management business, which were sold as of September 30, 2018 . For the nine months ended September 30, 2018 and 2017 , capital additions related to our Real Estate segment totaled $241.6 million and $243.3 million , respectively.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
Variable Interest Entities	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	Variable Interest Entities Generally, a variable interest entity, or VIE, is a legal entity in which the equity investors do not have the characteristics of a controlling financial interest or the equity investors lack sufficient equity at risk for the entity to finance its activities without additional subordinated financial support. A limited partnership is considered a VIE when the majority of the limited partners unrelated to the general partner possess neither the right to remove the general partner without cause, nor certain rights to participate in the decisions that most significantly affect the financial results of the partnership. In determining whether we are the primary beneficiary of a VIE, we consider qualitative and quantitative factors, including, but not limited to: which activities most significantly impact the VIE’s economic performance and which party controls such activities; the amount and characteristics of our investment; the obligation or likelihood for us or other investors to provide financial support; and the similarity with and significance to our business activities and the business activities of the other investors. Significant judgments related to these determinations include estimates about the current and future fair values and performance of real estate held by these VIEs and general market conditions. Aimco consolidates the Aimco Operating Partnership, which is a VIE for which Aimco is the primary beneficiary. Aimco, through the Aimco Operating Partnership, consolidates all VIEs for which the Aimco Operating Partnership is the primary beneficiary. All of the VIEs we consolidate own interests in one or more apartment communities. VIEs that own apartment communities we classify as part of our Real Estate segment are typically structured to generate a return for their partners through the operation and ultimate sale of the communities. We are the primary beneficiary in the limited partnerships in which we are the sole decision maker and have a substantial economic interest. The table below summarizes information regarding VIEs consolidated by the Aimco Operating Partnership: As described in Note 3 , we sold our Asset Management business in July 2018, including the nominal ownership interest we held in partnerships served by this business. September 30, 2018 December 31, 2017 Real Estate portfolio: VIEs with interests in apartment communities 9 14 Apartment communities owned by VIEs 9 14 Apartment homes in communities owned by VIEs 3,592 4,321 Consolidated partnerships served by Asset Management business: VIEs with interests in apartment communities — 49 Apartment communities owned by VIEs — 37 Apartment homes in communities owned by VIEs — 5,893 Assets of the Aimco Operating Partnership’s consolidated VIEs must first be used to settle the liabilities of such consolidated VIEs. These consolidated VIEs’ creditors do not have recourse to the general credit of the Aimco Operating Partnership. Assets and liabilities of consolidated VIEs are summarized in the table below (in thousands): September 30, 2018 December 31, 2017 Real Estate portfolio: Assets Net real estate $ 481,390 $ 529,898 Cash and cash equivalents 13,193 16,111 Restricted cash 7,295 4,798 Liabilities Non-recourse property debt secured by Real Estate communities, net 339,278 412,205 Accrued liabilities and other 17,096 10,623 Consolidated partnerships served by Asset Management business: Assets Real estate, net — 215,580 Cash and cash equivalents — 15,931 Restricted cash — 30,107 Liabilities Non-recourse property debt — 220,356 Accrued liabilities and other — 20,241

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted in accordance with such rules and regulations, although management believes the disclosures are adequate to prevent the information presented from being misleading. In the opinion of management, all adjustments (consisting of normal recurring items) considered necessary for a fair presentation have been included. Operating results for the three and nine months ended September 30, 2018 , are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 . The balance sheets of Aimco and the Aimco Operating Partnership at December 31, 2017 , have been derived from their respective audited financial statements at that date, but do not include all of the information and disclosures required by GAAP for complete financial statements. For further information, refer to the financial statements and notes thereto included in Aimco’s and the Aimco Operating Partnership’s combined Annual Report on Form 10-K for the year ended December 31, 2017 . Except where indicated, the footnotes refer to both Aimco and the Aimco Operating Partnership.
Principles of Consolidation	Principles of Consolidation Aimco’s accompanying condensed consolidated financial statements include the accounts of Aimco, the Aimco Operating Partnership, and their consolidated subsidiaries. The Aimco Operating Partnership’s condensed consolidated financial statements include the accounts of the Aimco Operating Partnership and its consolidated subsidiaries (see Note 8 ). All significant intercompany balances and transactions have been eliminated in consolidation. Interests in the Aimco Operating Partnership that are held by limited partners other than Aimco are reflected in Aimco’s accompanying condensed consolidated balance sheets as noncontrolling interests in the Aimco Operating Partnership. Interests in partnerships consolidated by the Aimco Operating Partnership that are held by third parties are reflected in our accompanying condensed consolidated balance sheets as noncontrolling interests in consolidated real estate partnerships.
Temporary Equity and Partners' Capital	The preferred OP Units may be redeemed at the holders’ option (as further discussed in Note 5 ), and are therefore presented within temporary equity in Aimco’s condensed consolidated balance sheets and within temporary capital in the Aimco Operating Partnership’s condensed consolidated balance sheets (in thousands).
Use of Estimates	Use of Estimates The preparation of our condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts included in the financial statements and accompanying notes thereto. Actual results could differ from those estimates.
Accounting Pronouncements Adopted in the Current Year	Accounting Pronouncements Adopted in the Current Year Effective January 1, 2018, we adopted a new standard issued by the Financial Accounting Standards Board, or FASB, that affects accounting for revenue. Under this new standard, revenue is generally recognized when an entity has transferred control of goods or services to a customer for an amount reflecting the consideration to which the entity expects to be entitled for such exchange. In evaluating the contracts we enter into in the ordinary course of business, substantially all of our revenue is generated by lease agreements, which will continue to be subject to existing GAAP until 2019, when we will adopt the new lease accounting standard. The new revenue standard also introduced new guidance for accounting for other income, including how we measure gains or losses on the sale of real estate. We adopted the new standard using the modified retrospective transition method effective January 1, 2018, with no effect on our results of operations or financial position. Effective January 1, 2018, we also adopted new standards issued by the FASB that affect the presentation and disclosure of the statements of cash flows. We are now required to present combined inflows and outflows of cash, cash equivalents, and restricted cash in the consolidated statement of cash flows. Previously our consolidated statements of cash flows presented transfers between restricted and unrestricted cash accounts as operating, financing, and investing cash activities depending upon the required or intended purpose for the restricted funds. The new guidance also requires debt prepayment and other extinguishment related payments to be classified as financing activities. We previously classified such payments as operating activities.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In 2018, the Securities Exchange Commission, or SEC, amended its rules to eliminate, modify, or integrate into other SEC requirements certain disclosure rules. The amendments are intended to simplify compliance without significantly changing the total mix of information provided to investors and are generally effective on November 5, 2018. The amendments remove the SEC rule that requires REITs to present gain or loss on the sale of real estate, net of income tax, in the statement of operations. Consistent with the SEC’s historical requirements, we present gain or loss on dispositions of real estate below continuing operations and net of tax. Accordingly we will recast our consolidated statements of operations to present gain or loss on dispositions of real estate as a component of income before income taxes beginning in our financial statements for the year ending December 31, 2018. Additionally, SEC rules currently require changes in equity subsequent to the prior year-end as either a separate financial statement or in the notes to interim financial statements. We present changes in equity within a footnote to our interim condensed consolidated financial statements in accordance with the SEC rule. The amendments create a requirement to report changes in equity and dividends per share in interim periods as a separate financial statement or within a footnote on a comparative basis for both quarter-to-date and year-to-date periods presented. This disclosure is required for interim financial statements of quarters beginning after the effective date; therefore, we will present comparative interim statements of stockholders equity beginning in our condensed consolidated financial statements for the three months ending March 31, 2019. In 2018, the FASB amended the new standard on lease accounting, which is effective for us on January 1, 2019. The amendment introduced an optional transition method, which allows the recognition of a cumulative-effect adjustment in the period of adoption and for prior reporting periods to remain as originally presented. Additionally, the amendment introduced a practical expedient for lessors to account for lease and nonlease components as a single component if the timing and pattern of transfer of components are the same, and the lease component would be classified as an operating lease if accounted for separately. We have substantially completed our evaluation of the amendment and expect to elect both the transition option and lessor practical expedient concurrent with our adoption of the standard. We do not anticipate significant changes in the timing of income from our leases with residents. However, in circumstances where we are a lessee, primarily a few ground leases and leases for corporate office space, we will be required to recognize right of use assets and related lease liabilities on our consolidated balance sheets. We are in the process of determining the amount of the right of use assets and related lease liabilities that will be recognized upon adoption.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Schedule of Equity [Line Items]
Reconciliation of consolidated temporary equity accounts	The following table presents a reconciliation of the Aimco Operating Partnership’s preferred OP Units from December 31, 2017 to September 30, 2018 . The preferred OP Units may be redeemed at the holders’ option (as further discussed in Note 5 ), and are therefore presented within temporary equity in Aimco’s condensed consolidated balance sheets and within temporary capital in the Aimco Operating Partnership’s condensed consolidated balance sheets (in thousands). Balance, December 31, 2017 $ 101,537 Distributions to holders of preferred OP Units (5,805 ) Redemption of preferred OP Units and other (217 ) Net income attributable to preferred OP Units 5,805 Balance, September 30, 2018 $ 101,320
Reconciliation of consolidated permanent equity accounts	The following table presents a reconciliation of Aimco’s consolidated permanent equity accounts from December 31, 2017 to September 30, 2018 (in thousands): Aimco Equity Noncontrolling interests in consolidated real estate partnerships Common noncontrolling interests in Aimco Operating Partnership Total Equity Balance, December 31, 2017 $ 1,663,144 $ (1,716 ) $ (5,675 ) $ 1,655,753 Issuance of common OP Units — — 50,151 50,151 Dividends on Preferred Stock (6,445 ) — — (6,445 ) Dividends and distributions on Common Stock and common OP Units (179,351 ) (7,934 ) (9,402 ) (196,687 ) Redemptions of common OP Units — — (8,458 ) (8,458 ) Amortization of stock-based compensation cost 6,285 — 1,236 7,521 Effect of changes in ownership for consolidated entities (18,137 ) — 8,036 (10,101 ) Change in accumulated other comprehensive loss 1,247 — 72 1,319 Other 119 — — 119 Net income 658,820 8,045 34,093 700,958 Balance, September 30, 2018 $ 2,125,682 $ (1,605 ) $ 70,053 $ 2,194,130
Revisions to net cash flows from operating, investing, and financing activities	We have revised our condensed consolidated statements of cash flows for the nine months ended September 30, 2017 to conform to this presentation, and the effect of the revisions to net cash flows from operating, investing, and financing activities as previously reported for the nine months ended September 30, 2017 are summarized in the following table (in thousands): As Previously Reported Adjustments As Revised Net cash provided by operating activities $ 285,025 $ 10,124 $ 295,149 Net cash used in investing activities (274,139 ) (1,746 ) (275,885 ) Net cash used in financing activities (16,449 ) (369 ) (16,818 )
AIMCO PROPERTIES, L.P [Member]
Schedule of Equity [Line Items]
Reconciliation of consolidated permanent equity accounts	The following table presents a reconciliation of the consolidated partners’ capital balances in permanent capital that are attributable to the Aimco Operating Partnership from December 31, 2017 to September 30, 2018 (in thousands): Partners’ capital attributable to the Aimco Operating Partnership Balance, December 31, 2017 $ 1,657,469 Issuance of common OP Units 50,151 Distributions to preferred units held by Aimco (6,445 ) Distributions to common units held by Aimco (179,351 ) Distributions to common units held by Limited Partners (9,402 ) Redemption of common OP Units (8,458 ) Amortization of Aimco stock-based compensation cost 7,521 Effect of changes in ownership for consolidated entities (10,101 ) Change in accumulated other comprehensive loss 1,319 Other 119 Net income 692,913 Balance, September 30, 2018 $ 2,195,735

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
Fair Value Measurements (Tables)	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table sets forth a summary of the changes in fair value of these interest rate swaps (in thousands): Nine Months Ended September 30, 2018 2017 Beginning balance $ (1,795 ) $ (3,175 ) Realized losses included in interest expense 404 73 Realized losses on derecognition of interest rate swaps 1,115 273 Losses on interest rate swaps reclassified into interest expense from accumulated other comprehensive loss 276 1,076 Unrealized losses included in equity and partners’ capital — (280 ) Ending balance $ — $ (2,033 )

Business Segments (Tables)

Business Segments (Tables)	9 Months Ended
Business Segments (Tables)	Sep. 30, 2018
Segment Reporting [Abstract]
Summary information for the reportable segments	The following tables present the revenues, net operating income and income before gain on dispositions of our Real Estate segment on a proportionate basis and excluding amounts related to apartment communities sold as of September 30, 2018 for the three and nine months ended September 30, 2018 and 2017 (in thousands): Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Reportable Segment (2) Consolidated Three months ended September 30, 2018: Rental and other property revenues attributable to Real Estate $ 222,856 $ 8,926 $ 2,266 $ 234,048 Rental and other property revenues of partnerships served by Asset Management business — — 5,022 5,022 Tax credit and transaction revenues — — 3,411 3,411 Total revenues 222,856 8,926 10,699 242,481 Property operating expenses attributable to Real Estate 62,863 8,405 6,986 78,254 Property operating expenses of partnerships served by Asset Management business — — 2,608 2,608 Other operating expenses not allocated to reportable segment (3) — — 114,665 114,665 Total operating expenses 62,863 8,405 124,259 195,527 Operating income 159,993 521 (113,560 ) 46,954 Other items included in income before gain on dispositions (4) — — (15,122 ) (15,122 ) Income before gain on dispositions $ 159,993 $ 521 $ (128,682 ) $ 31,832 Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Reportable Segment (2) Consolidated Three months ended September 30, 2017: Rental and other property revenues attributable to Real Estate $ 203,935 $ 8,155 $ 21,618 $ 233,708 Rental and other property revenues of partnerships served by Asset Management business — — 18,232 18,232 Tax credit and transaction revenues — — 2,695 2,695 Total revenues 203,935 8,155 42,545 254,635 Property operating expenses attributable to Real Estate 57,592 7,609 16,043 81,244 Property operating expenses of partnerships served by Asset Management business — — 8,872 8,872 Other operating expenses not allocated to reportable segment (3) — — 105,314 105,314 Total operating expenses 57,592 7,609 130,229 195,430 Operating income 146,343 546 (87,684 ) 59,205 Other items included in income before gain on dispositions (4) — — (36,828 ) (36,828 ) Income before gain on dispositions $ 146,343 $ 546 $ (124,512 ) $ 22,377 Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Reportable Segment (2) Consolidated Nine months ended September 30, 2018: Rental and other property revenues attributable to Real Estate $ 643,656 $ 25,903 $ 21,012 $ 690,571 Rental and other property revenues of partnerships served by Asset Management business — — 42,830 42,830 Tax credit and transaction revenues — — 6,987 6,987 Total revenues 643,656 25,903 70,829 740,388 Property operating expenses attributable to Real Estate 183,119 24,337 25,116 232,572 Property operating expenses of partnerships served by Asset Management business — — 20,865 20,865 Other operating expenses not allocated to reportable segment (3) — — 337,259 337,259 Total operating expenses 183,119 24,337 383,240 590,696 Operating income 460,537 1,566 (312,411 ) 149,692 Other items included in income before gain on dispositions (4) — — (65,560 ) (65,560 ) Income before gain on dispositions $ 460,537 $ 1,566 $ (377,971 ) $ 84,132 Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Reportable Segment (2) Consolidated Nine months ended September 30, 2017: Rental and other property revenues attributable to Real Estate $ 589,349 $ 35,542 $ 61,748 $ 686,639 Rental and other property revenues of partnerships served by Asset Management business — — 55,327 55,327 Tax credit and transaction revenues — — 8,242 8,242 Total revenues 589,349 35,542 125,317 750,208 Property operating expenses attributable to Real Estate 169,311 25,505 45,138 239,954 Property operating expenses of partnerships served by Asset Management business — — 26,458 26,458 Other operating expenses not allocated to reportable segment (3) — — 307,096 307,096 Total operating expenses 169,311 25,505 378,692 573,508 Operating income 420,038 10,037 (253,375 ) 176,700 Other items included in income before gain on dispositions (4) — — (116,691 ) (116,691 ) Income before gain on dispositions $ 420,038 $ 10,037 $ (370,066 ) $ 60,009 (1) Represents adjustments for the noncontrolling interests in consolidated real estate partnerships’ share of the results of consolidated apartment communities in our Real Estate segment, which are included in the related consolidated amounts, but excluded from proportionate property net operating income for our segment evaluation. Also includes the reclassification of utility reimbursements from revenues to property operating expenses for the purpose of evaluating segment results. Utility reimbursements are included in rental and other property revenues in our condensed consolidated statements of operations prepared in accordance with GAAP. (2) Includes the operating results of apartment communities sold during the periods shown or held for sale at the end of the period, if any, and the operating results of apartment communities owned by consolidated partnerships served by our Asset Management business prior to its sale in July 2018. Corporate and Amounts Not Allocated to Reportable Segment also includes property management expenses and casualty gains and losses, which are included in consolidated property operating expenses and are not part of our segment performance measure. (3) Other operating expenses not allocated to reportable segment consists of depreciation and amortization, general and administrative expenses and other operating expenses, which are not included in our measure of segment performance. (4) Other items included in income before gain on dispositions primarily consists of interest and income tax benefit.
Reconciliation of Assets from Segment to Consolidated [Table Text Block]	The assets of our reportable segment and the consolidated assets not allocated to our segment are as follows (in thousands): September 30, 2018 December 31, 2017 Real Estate $ 5,861,647 $ 5,391,816 Corporate and other assets (1) 323,374 687,224 Total consolidated assets $ 6,185,021 $ 6,079,040 (1) Includes the assets not allocated to our reportable segment, primarily corporate assets, and as of December 31, 2017 , assets of apartment communities and the Asset Management business, which were sold as of September 30, 2018 .

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
Variable Interest Entities (Tables)	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Variable Interest Entities	The table below summarizes information regarding VIEs consolidated by the Aimco Operating Partnership: As described in Note 3 , we sold our Asset Management business in July 2018, including the nominal ownership interest we held in partnerships served by this business. September 30, 2018 December 31, 2017 Real Estate portfolio: VIEs with interests in apartment communities 9 14 Apartment communities owned by VIEs 9 14 Apartment homes in communities owned by VIEs 3,592 4,321 Consolidated partnerships served by Asset Management business: VIEs with interests in apartment communities — 49 Apartment communities owned by VIEs — 37 Apartment homes in communities owned by VIEs — 5,893 Assets of the Aimco Operating Partnership’s consolidated VIEs must first be used to settle the liabilities of such consolidated VIEs. These consolidated VIEs’ creditors do not have recourse to the general credit of the Aimco Operating Partnership. Assets and liabilities of consolidated VIEs are summarized in the table below (in thousands): September 30, 2018 December 31, 2017 Real Estate portfolio: Assets Net real estate $ 481,390 $ 529,898 Cash and cash equivalents 13,193 16,111 Restricted cash 7,295 4,798 Liabilities Non-recourse property debt secured by Real Estate communities, net 339,278 412,205 Accrued liabilities and other 17,096 10,623 Consolidated partnerships served by Asset Management business: Assets Real estate, net — 215,580 Cash and cash equivalents — 15,931 Restricted cash — 30,107 Liabilities Non-recourse property debt — 220,356 Accrued liabilities and other — 20,241

Organization (Details Textual)

Organization (Details Textual)	9 Months Ended
Organization (Details Textual)	Sep. 30, 2018communityUnitsPropertyshares
Organization [Line Items]
Common partnership units and equivalents outstanding \| shares	157,352,109
Percentage of the Aimco Operating Partnership's common partnership units and equivalents owned by Aimco	94.60%
AIMCO PROPERTIES, L.P [Member]
Organization [Line Items]
Common partnership units and equivalents outstanding \| shares	166,384,727
Aimco Real Estate [Member] \| Partially Owned Properties [Member]
Organization [Line Items]
Number of apartment communities \| Property	133
Number of apartment homes in apartment communities \| Units	36,481
Aimco Real Estate [Member] \| Wholly And Partially Owned Consolidated Properties [Member]
Organization [Line Items]
Number of apartment communities \| Property	129
Number of apartment homes in apartment communities \| Units	36,339
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Aimco Real Estate [Member] \| Wholly And Partially Owned Consolidated Properties [Member]
Organization [Line Items]
Number of apartment communities \| Property	4
Number of apartment homes in apartment communities \| Units	1,334
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Hunters Point Affordable Apartment Communities [Member] \| Wholly And Partially Owned Consolidated Properties [Member]
Organization [Line Items]
Number of apartment communities \| community	4

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 104,299	$ 142,541	$ 133,596	$ 131,150

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance, December 31, 2017	$ 101,537
Balance, September 30, 2018	101,320
AIMCO PROPERTIES, L.P [Member]
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance, December 31, 2017	101,537
Distributions to holders of preferred OP Units	(5,805)
Redemption of preferred OP Units and other	(217)
Net income attributable to preferred OP Units	5,805
Balance, September 30, 2018	$ 101,320

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies (Details 1) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, December 31, 2017	$ 1,655,753
Common units issued during period, value	50,151
Dividends on Preferred Stock	(6,445)
Dividends and distributions on Common Stock and common OP Units	(196,687)
Redemptions of common OP Units	(8,458)
Amortization of stock-based compensation cost	7,521
Effect of changes in ownership for consolidated entities	(10,101)
Change in accumulated other comprehensive loss	1,319
Other	119
Net income	700,958
Balance, September 30, 2018	2,194,130
Aimco Equity [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, December 31, 2017	1,663,144
Dividends on Preferred Stock	(6,445)
Dividends and distributions on Common Stock and common OP Units	(179,351)
Amortization of stock-based compensation cost	6,285
Effect of changes in ownership for consolidated entities	(18,137)
Change in accumulated other comprehensive loss	1,247
Other	119
Net income	658,820
Balance, September 30, 2018	2,125,682
Noncontrolling Interests in Consolidated Real Estate Partnerships [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, December 31, 2017	(1,716)
Dividends and distributions on Common Stock and common OP Units	(7,934)
Net income	8,045
Balance, September 30, 2018	(1,605)
Common Noncontrolling Interests in Aimco Operating Partnership [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, December 31, 2017	(5,675)
Common units issued during period, value	50,151
Dividends and distributions on Common Stock and common OP Units	(9,402)
Redemptions of common OP Units	(8,458)
Amortization of stock-based compensation cost	1,236
Effect of changes in ownership for consolidated entities	8,036
Change in accumulated other comprehensive loss	72
Net income	34,093
Balance, September 30, 2018	$ 70,053

Basis of Presentation and Sum_6

Basis of Presentation and Summary of Significant Accounting Policies (Details 2) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Increase (Decrease) in Partners' Capital [Roll Forward]
Common units issued during period, value	$ 50,151
Redemption of common OP Units	(8,458)
Amortization of Aimco stock-based compensation cost	7,521
Effect of changes in ownership for consolidated entities	(10,101)
Change in accumulated other comprehensive loss	1,319
Other	119
Net income	700,958
AIMCO Properties, LP [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance, December 31, 2017	1,657,469
Balance, September 30, 2018	2,195,735
AIMCO Properties, LP [Member] \| Partners Capital [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Balance, December 31, 2017	1,657,469
Common units issued during period, value	50,151
Distributions to preferred units held by Aimco	(6,445)
Distributions to common units held by Aimco	(179,351)
Distributions to common units held by Limited Partners	(9,402)
Redemption of common OP Units	(8,458)
Amortization of Aimco stock-based compensation cost	7,521
Effect of changes in ownership for consolidated entities	(10,101)
Change in accumulated other comprehensive loss	1,319
Other	119
Net income	692,913
Balance, September 30, 2018	$ 2,195,735

Basis of Presentation and Sum_7

Basis of Presentation and Summary of Significant Accounting Policies (Details 3) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities	$ 302,926	$ 295,149
Net cash used in investing activities	239,122	(275,885)
Net Cash Provided by (Used in) Financing Activities	$ (580,290)	(16,818)
As Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities		285,025
Net cash used in investing activities		(274,139)
Net Cash Provided by (Used in) Financing Activities		(16,449)
Accounting Standards Update 2016-18 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities		10,124
Net cash used in investing activities		(1,746)
Net Cash Provided by (Used in) Financing Activities		$ (369)

Significant Transactions, Dis_2

Significant Transactions, Dispositions of Apartment Communities and Assets Held for Sale (Details Textual) $ / shares in Units, ft² in Thousands, $ in Thousands, shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)ft²communityUnitsPropertyshares	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)ft²communityUnitsProperty	Sep. 30, 2017USD ($)	May 01, 2018Property$ / shares	Dec. 31, 2017USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest in Limited Partnerships	$ (1,605)		$ (1,605)			$ (1,716)
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	572,085	$ (233)	622,631	$ 881
Assets	6,185,021		6,185,021			6,079,040
Liabilities	$ 3,889,571		$ 3,889,571			$ 4,321,750
Wholly And Partially Owned Consolidated Properties [Member] \| Assets Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of apartment communities \| Property	1		1
Bent Tree Apartments - Fairfax County, Virginia [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total fair value allocated to land	$ 47,000		$ 47,000
Total fair value allocated to building and improvements	113,000		113,000
Total fair value allocated to other items	$ 1,000		1,000
Payments to acquire and develop real estate			$ 160,000
Number of apartment homes in apartment communities \| Units	748		748
Capitalized asset acquisition costs			$ 1,000
2018 Philadelphia Acquisition Portfolio [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total fair value allocated to land	$ 14,100		14,100
Total fair value allocated to building and improvements	289,700		289,700
Asset Acquisition Recognized Identifiable Assets Acquired and Liabilities Assumed Intangible Assets	8,300		8,300
Asset Acquisition Recognized Identifiable Assets Acquired And Liabilities Assumed Intangible Liabilities	$ 12,300		$ 12,300
Number of apartment homes in apartment communities \| Units	665		665
Area of office and retail space acquired (in square feet) \| ft²	153		153
Asset Acquisition Recognized Identifiable Assets Acquired and Liabilities Assumed Non-Recourse Property Debt	$ 208,900		$ 208,900
Common units issued during period \| shares	1.2
Asset Acquisition, Share Price \| $ / shares					$ 41.08
Capitalized asset acquisition costs			6,400
Number of apartment communities \| Property					4
La Jolla Cove [Member] \| Wholly And Partially Owned Consolidated Properties [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Notional value of seller financing provided	$ 48,600		48,600
Net cash proceeds from the sale of real estate with seller financing provided			$ 5,000
Hunters Point Affordable Apartment Communities [Member] \| Wholly And Partially Owned Consolidated Properties [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of apartment communities \| community	4		4
Aimco Real Estate [Member] \| Wholly And Partially Owned Consolidated Properties [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of apartment homes in apartment communities \| Units	36,339		36,339
Number of apartment communities \| Property	129		129
Aimco Real Estate [Member] \| Wholly And Partially Owned Consolidated Properties [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of apartment homes in apartment communities \| Units	1,334		1,334
Gain on dispositions of real estate, applicable income taxes			$ 54,100
Net proceeds to Aimco from the sale of real estate			230,100
Gain on dispositions of real estate			173,200
Gross proceeds from sale of real estate			$ 242,300
Number of apartment communities \| Property	4		4
Asset Management [Member] \| Wholly And Partially Owned Consolidated Properties [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes			$ 448,200
Asset Management [Member] \| Wholly And Partially Owned Consolidated Properties [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net proceeds to Aimco from the sale of real estate			512,200
Gross proceeds from sale of real estate			$ 590,000

Commitments and Contingencies (

Commitments and Contingencies (Details Textual) $ in Millions	1 Months Ended	9 Months Ended
	May 31, 2017parties	Sep. 30, 2018USD ($)
Long-term Purchase Commitment [Line Items]
Number of potentially responsible parties, environmental remediation \| parties	4
Commitments related to development, redevelopment and capital improvement activities [Member]
Long-term Purchase Commitment [Line Items]
Commitments related to capital spending activities \| $		$ 130.6
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

Earnings per Share_Unit (Detail

Earnings per Share/Unit (Details Textual) - USD ($) $ in Thousands, shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive potential common shares/units (in shares)	0.2	0.5	0.2	0.5
Antidilutive securities excluded from the denominator for calculating dilutive earnings per share and per unit (in shares)	0.2	0.2	0.2	0.2
Participating securities outstanding (in shares)	0.3	0.2	0.3	0.2
Preferred noncontrolling interests in Aimco Operating Partnership	$ 101,320		$ 101,320		$ 101,537
Number of shares potentially redeemable for (in shares)	2.3		2.3
AIMCO Properties, LP [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive potential common shares/units (in shares)	0.2	0.5	0.2	0.5
Antidilutive securities excluded from the denominator for calculating dilutive earnings per share and per unit (in shares)	0.2	0.2	0.2	0.2
Preferred noncontrolling interests in Aimco Operating Partnership	$ 101,320		$ 101,320		$ 101,537

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Interest Rate Swap [Member] - Fair Value, Inputs, Level 2 [Member] - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 404	$ 73
Fair Value Assets and Liabilities Measured on Recurring Basis Fair value and input reconciliation [Roll Forward]
Cash flow hedge fair value, beginning balance	(1,795)	(3,175)
Realized losses on derecognition of interest rate swaps	1,115	273
Losses on interest rate swaps reclassified into interest expense from accumulated other comprehensive loss	276	1,076
Unrealized losses included in equity and partners’ capital	0	(280)
Cash flow hedge fair value, ending balance	$ 0	$ (2,033)

Fair Value Measurements (Deta_2

Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Available-for-sale Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Face amount of investment in available-for-sale debt securities	$ 100,900
Excepted remaining term of available for sale securities	2 years 8 months
Amortized cost of the investment in available-for-sale debt securities	$ 82,100	$ 77,700
Available-for-sale Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage-backed securities available-for-sale, fair value disclosure	87,000	82,800
Aimco Real Estate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated fair value of consolidated debt	3,600,000
Total indebtedness associated with Real Estate portfolio	3,646,789	3,861,770
Non-recourse property debt, net	3,646,789	3,545,109
Asset Management [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Non-recourse property debt, net	$ 0	$ 227,141

Business Segments (Details Text

Business Segments (Details Textual) $ in Millions	9 Months Ended
Business Segments (Details Textual) $ in Millions	Sep. 30, 2018USD ($)UnitsPropertySegment	Sep. 30, 2017USD ($)	Dec. 31, 2017UnitsProperty
Business Segments (Textual) [Abstract]
Number of reportable segments \| Segment	1
Operating Segments [Member] \| Aimco Real Estate [Member]
Business Segments (Textual) [Abstract]
Capital additions related to segments \| $	$ 241.6	$ 243.3
Partially Owned Properties [Member] \| Aimco Real Estate [Member]
Business Segments (Textual) [Abstract]
Number of owned and managed apartment communities in segments \| Property	133
Number of apartment homes in apartment communities \| Units	36,481
Wholly And Partially Owned Consolidated Properties [Member] \| Aimco Real Estate [Member]
Business Segments (Textual) [Abstract]
Number of owned and managed apartment communities in segments \| Property	129
Number of apartment homes in apartment communities \| Units	36,339
Unconsolidated Properties [Member] \| Aimco Real Estate [Member]
Business Segments (Textual) [Abstract]
Number of owned and managed apartment communities in segments \| Property	4
Number of apartment homes in apartment communities \| Units	142
Aimco Real Estate [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Business Segments (Textual) [Abstract]
Number of owned and managed apartment communities in segments \| Property	9		14
Number of apartment homes in apartment communities \| Units	3,592		4,321

Business Segments (Details)

Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Business Segments (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Summary information for the reportable segments
Tax credit and transaction revenues	$ 3,411	$ 2,695	$ 6,987	$ 8,242
Total revenues	242,481	254,635	740,388	750,208
Depreciation and amortization	96,406	92,513	286,439	268,836
General and administrative expenses	12,479	10,529	37,196	31,599
Other operating expenses not allocated to reportable segment (3)	114,665	105,314	337,259	307,096
Total operating expenses	195,527	195,430	590,696	573,508
Net operating income (loss)	46,954	59,205	149,692	176,700
Other Items included in income before gain on dispositions (4)	(15,122)	(36,828)	(65,560)	(116,691)
Income before gain (loss) on dispositions	31,832	22,377	84,132	60,009
Aimco Real Estate [Member]
Summary information for the reportable segments
Rental and other property revenues	234,048	233,708	690,571	686,639
Property operating expenses	78,254	81,244	232,572	239,954
Operating Segments [Member] \| Aimco Real Estate [Member]
Summary information for the reportable segments
Rental and other property revenues	222,856	203,935	643,656	589,349
Total revenues	222,856	203,935	643,656	589,349
Property operating expenses	62,863	57,592	183,119	169,311
Total operating expenses	62,863	57,592	183,119	169,311
Net operating income (loss)	159,993	146,343	460,537	420,038
Income before gain (loss) on dispositions	159,993	146,343	460,537	420,038
Segment Reconciling Items [Member]
Summary information for the reportable segments
Total revenues	8,926	8,155	25,903	35,542
Total operating expenses	8,405	7,609	24,337	25,505
Net operating income (loss)	521	546	1,566	10,037
Income before gain (loss) on dispositions	521	546	1,566	10,037
Segment Reconciling Items [Member] \| Aimco Real Estate [Member]
Summary information for the reportable segments
Rental and other property revenues	8,926	8,155	25,903	35,542
Property operating expenses	8,405	7,609	24,337	25,505
Corporate Non-Segment [Member]
Summary information for the reportable segments
Tax credit and transaction revenues	3,411	2,695	6,987	8,242
Total revenues	10,699	42,545	70,829	125,317
Other operating expenses not allocated to reportable segment (3)	114,665	105,314	337,259	307,096
Total operating expenses	124,259	130,229	383,240	378,692
Net operating income (loss)	(113,560)	(87,684)	(312,411)	(253,375)
Other Items included in income before gain on dispositions (4)	(15,122)	(36,828)	(65,560)	(116,691)
Income before gain (loss) on dispositions	(128,682)	(124,512)	(377,971)	(370,066)
Corporate Non-Segment [Member] \| Aimco Real Estate [Member]
Summary information for the reportable segments
Rental and other property revenues	2,266	21,618	21,012	61,748
Property operating expenses	6,986	16,043	25,116	45,138
Asset Management [Member]
Summary information for the reportable segments
Rental and other property revenues	5,022	18,232	42,830	55,327
Property operating expenses	2,608	8,872	20,865	26,458
Asset Management [Member] \| Operating Segments [Member] \| Aimco Real Estate [Member]
Summary information for the reportable segments
Rental and other property revenues	0	0	0	0
Property operating expenses	0	0	0	0
Asset Management [Member] \| Corporate Non-Segment [Member]
Summary information for the reportable segments
Rental and other property revenues	5,022	18,232	42,830	55,327
Property operating expenses	$ 2,608	$ 8,872	$ 20,865	$ 26,458

Business Segments (Details 1)

Business Segments (Details 1) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total assets	$ 6,185,021	$ 6,079,040
Operating Segments [Member] \| Aimco Real Estate [Member]
Segment Reporting Information [Line Items]
Total assets	5,861,647	5,391,816
Corporate Non-Segment [Member]
Segment Reporting Information [Line Items]
Total assets	$ 323,374	$ 687,224

Variable Interest Entities (Det

Variable Interest Entities (Details) - Variable Interest Entity, Primary Beneficiary [Member] $ in Thousands	Sep. 30, 2018USD ($)UnitsPropertyEntity	Dec. 31, 2017USD ($)UnitsPropertyEntity
Aimco Real Estate [Member]
Variable Interest Entity [Line Items]
Number of consolidated variable interest entities \| Entity	9	14
Number of apartment communities \| Property	9	14
Number of apartment homes owned by VIEs \| Units	3,592	4,321
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Net real estate	$ 481,390	$ 529,898
Cash and cash equivalents	13,193	16,111
Restricted cash	7,295	4,798
Non-recourse property debt secured by Real Estate communities, net	339,278	412,205
Accrued liabilities and other	$ 17,096	$ 10,623
Asset Management [Member]
Variable Interest Entity [Line Items]
Number of consolidated variable interest entities \| Entity	0	49
Number of apartment communities \| Property	0	37
Number of apartment homes owned by VIEs \| Units	0	5,893
Assets Held-for-sale [Member] \| Asset Management [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Net real estate	$ 0	$ 215,580
Cash and cash equivalents	0	15,931
Restricted cash	0	30,107
Non-recourse property debt secured by Real Estate communities, net	0	220,356
Accrued liabilities and other	$ 0	$ 20,241