Apartment Investment and Management (AIV) 10-Q 6 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 02, 2019
Entity Registrant Name	APARTMENT INVESTMENT & MANAGEMENT CO
Entity Central Index Key	0000922864
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		148,828,469
AIMCO Properties, LP [Member]
Entity Registrant Name	AIMCO PROPERTIES LP
Entity Central Index Key	0000926660
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		158,492,651

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
ASSETS
Buildings and improvements	$ 6,493,539	$ 6,552,065
Land	1,731,980	1,756,525
Total real estate	8,225,519	8,308,590
Accumulated depreciation	(2,581,666)	(2,585,115)
Net real estate	5,643,853	5,723,475
Cash and cash equivalents	162,286	36,858
Restricted cash	36,103	35,737
Other assets	441,527	351,541
Assets held for sale	0	42,393
Total assets	6,283,769	6,190,004
LIABILITIES AND EQUITY
Non-recourse property debt, net	3,859,023	3,915,305
Revolving credit facility borrowings	70,000	160,360
Total indebtedness	3,929,023	4,075,665
Accrued liabilities and other	293,279	226,230
Liabilities related to assets held for sale	0	23,177
Total liabilities	4,222,302	4,325,072
Preferred noncontrolling interests/Redeemable Preferred Units	101,195	101,291
Commitments and contingencies (Note 5)
Equity/Partners' Capital:
Perpetual Preferred Stock	125,000	125,000
Common Stock, $0.01 par value, 500,787,260 shares authorized, 148,758,031 and 144,623,034 shares issued/outstanding at March 31, 2019 and December 31, 2018, respectively	1,488	1,446
Additional paid-in capital	3,495,295	3,515,686
Accumulated other comprehensive income	4,851	4,794
Distributions in excess of earnings	(1,742,998)	(1,947,507)
Total Aimco equity	1,883,636	1,699,419
Noncontrolling interests in consolidated real estate partnerships	(2,857)	(2,967)
Common noncontrolling interests in Aimco Operating Partnership	79,493	67,189
Total equity	1,960,272	1,763,641
Total liabilities and equity	6,283,769	6,190,004
AIMCO Properties, LP [Member]
ASSETS
Buildings and improvements	6,493,539	6,552,065
Land	1,731,980	1,756,525
Total real estate	8,225,519	8,308,590
Accumulated depreciation	(2,581,666)	(2,585,115)
Net real estate	5,643,853	5,723,475
Cash and cash equivalents	162,286	36,858
Restricted cash	36,103	35,737
Other assets	441,527	351,541
Assets held for sale	0	42,393
Total assets	6,283,769	6,190,004
LIABILITIES AND EQUITY
Non-recourse property debt, net	3,859,023	3,915,305
Revolving credit facility borrowings	70,000	160,360
Total indebtedness	3,929,023	4,075,665
Accrued liabilities and other	293,279	226,230
Liabilities related to assets held for sale	0	23,177
Total liabilities	4,222,302	4,325,072
Preferred noncontrolling interests/Redeemable Preferred Units	101,195	101,291
Commitments and contingencies (Note 5)
Equity/Partners' Capital:
Preferred units	125,000	125,000
General Partner and Special Limited Partner	1,758,636	1,574,419
Limited Partners	79,493	67,189
Partners’ capital attributable to the Aimco Operating Partnership	1,963,129	1,766,608
Partners' Capital Attributable to Noncontrolling Interest	(2,857)	(2,967)
Total partners’ capital	1,960,272	1,763,641
Total liabilities and equity	$ 6,283,769	$ 6,190,004

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
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)	148,758,031	144,623,034
Common Stock, shares outstanding (in shares)	148,758,031	144,623,034

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
REVENUES
Rental and other property revenues	$ 230,235	$ 225,393
Tax credit and transaction revenues	0	22,327
Total revenues	230,235	247,720
OPERATING EXPENSES
Property operating expenses	79,184	78,287
Direct Costs of Leased and Rented Property or Equipment - Asset Management	0	9,195
Depreciation and amortization	93,565	92,548
General and administrative expenses	10,369	11,355
Other expenses, net	5,703	2,958
Total operating expenses	188,821	194,343
Interest income	2,726	2,172
Interest expense	(41,409)	(47,795)
Other, net	72	224
Income before income tax (expense) benefit	294,276	61,173
Income tax (expense) benefit	(2,981)	34,517
Gain (loss) on dispositions of real estate and the Asset Management business, inclusive of related income tax	291,473	53,195
Net income	291,295	95,690
Noncontrolling interests:
Net income attributable to noncontrolling interests in consolidated real estate partnerships	(91)	(6,206)
Net income attributable to preferred noncontrolling interests in Aimco Operating Partnership	(1,934)	(1,937)
Net income attributable to common noncontrolling interests in Aimco Operating Partnership	(15,137)	(3,755)
Net income attributable to noncontrolling interests	(17,162)	(11,898)
Net income attributable to the company	274,133	83,792
Net income attributable to the company's preferred equity holders	(2,148)	(2,148)
Net income attributable to participating securities	(417)	(119)
Net income attributable to the company's common equity holders	$ 271,568	$ 81,525
Earnings attributable to the company per common share/unit
Net income attributable to the company per common share/unit - basic and diluted (in dollars per share/unit)	$ 1.88	$ 0.54
Weighted average number of shares outstanding - basic	144,232	151,872
Weighted average number of shares outstanding - diluted	144,445	152,000
Gain (Loss) on Sale of Properties, before Applicable Income Taxes	$ 291,473	$ 53,195
AIMCO Properties, LP [Member]
REVENUES
Rental and other property revenues	230,235	225,393
Tax credit and transaction revenues	0	22,327
Total revenues	230,235	247,720
OPERATING EXPENSES
Property operating expenses	79,184	78,287
Direct Costs of Leased and Rented Property or Equipment - Asset Management	0	9,195
Depreciation and amortization	93,565	92,548
General and administrative expenses	10,369	11,355
Other expenses, net	5,703	2,958
Total operating expenses	188,821	194,343
Interest income	2,726	2,172
Interest expense	(41,409)	(47,795)
Other, net	72	224
Income before income tax (expense) benefit	294,276	61,173
Income tax (expense) benefit	(2,981)	34,517
Gain (loss) on dispositions of real estate and the Asset Management business, inclusive of related income tax	291,473	53,195
Net income	291,295	95,690
Noncontrolling interests:
Net income attributable to noncontrolling interests in consolidated real estate partnerships	(91)	(6,206)
Net income attributable to the company	291,204	89,484
Net income attributable to the company's preferred equity holders	(4,082)	(4,085)
Net income attributable to participating securities	(483)	(125)
Net income attributable to the company's common equity holders	$ 286,639	$ 85,274
Earnings attributable to the company per common share/unit
Net income attributable to the company per common share/unit - basic and diluted (in dollars per share/unit)	$ 1.88	$ 0.54
Weighted average number of shares outstanding - basic	152,303	158,875
Weighted average number of shares outstanding - diluted	152,632	159,006

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net income	$ 291,295	$ 95,690
Other comprehensive gain (loss):
Losses on interest rate swaps reclassified into earnings from accumulated other comprehensive loss	0	119
Unrealized gains (losses) on available for sale debt securities	61	(600)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	0	419
Other comprehensive gain (loss)	61	(62)
Comprehensive income	291,356	95,628
Comprehensive income attributable to noncontrolling interests	(17,166)	(11,895)
Comprehensive income attributable to Aimco/Operating Partnership	274,190	83,733
AIMCO Properties, LP [Member]
Net income	291,295	95,690
Other comprehensive gain (loss):
Losses on interest rate swaps reclassified into earnings from accumulated other comprehensive loss	0	119
Unrealized gains (losses) on available for sale debt securities	61	(600)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	0	419
Other comprehensive gain (loss)	61	(62)
Comprehensive income	291,356	95,628
Comprehensive income attributable to noncontrolling interests	(91)	(6,206)
Comprehensive income attributable to Aimco/Operating Partnership	$ 291,265	$ 89,422

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 291,295	$ 95,690
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	93,565	92,548
Gain (loss) on dispositions of real estate and the Asset Management business, inclusive of related income tax	(291,473)	(53,195)
Income Tax Expense (Benefit)	2,981	(34,517)
Other adjustments	3,201	284
Net changes in operating assets and operating liabilities	(17,952)	(19,487)
Net cash provided by operating activities	81,617	81,323
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of real estate and deposits related to purchases of real estate	(2,236)	(164,650)
Capital expenditures	(85,546)	(75,601)
Proceeds from dispositions of real estate	342,083	69,788
Purchases of corporate assets	(3,319)	(947)
Other investing activities	1,422	(218)
Net cash provided by (used in) investing activities	252,404	(171,628)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from non-recourse property debt	0	360,613
Principal repayments of non-recourse property debt	(19,580)	(206,262)
Net (repayments of) borrowings on revolving credit facility	(90,360)	11,475
Repurchases of Common Stock	(20,682)	0
Payment of dividends to holders of Preferred Stock	(2,148)	(2,148)
Payment of distributions to noncontrolling interests	(5,701)	(11,902)
Payment of distributions to noncontrolling interests	(67,405)	(59,652)
Redemptions of noncontrolling interests in the Aimco Operating Partnership	(2,653)	(7,122)
Purchases and redemptions of noncontrolling interests	0	(1,219)
Other financing activities	(302)	(3,012)
Net cash (used in) provided by financing activities	(208,227)	86,795
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	125,794	(3,510)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT BEGINNING OF PERIOD	72,595	142,541
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT END OF PERIOD	198,389	139,031
AIMCO Properties, LP [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	291,295	95,690
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	93,565	92,548
Gain (loss) on dispositions of real estate and the Asset Management business, inclusive of related income tax	(291,473)	(53,195)
Income Tax Expense (Benefit)	2,981	(34,517)
Other adjustments	3,201	284
Net changes in operating assets and operating liabilities	(17,952)	(19,487)
Net cash provided by operating activities	81,617	81,323
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of real estate and deposits related to purchases of real estate	(2,236)	(164,650)
Capital expenditures	(85,546)	(75,601)
Proceeds from dispositions of real estate	342,083	69,788
Purchases of corporate assets	(3,319)	(947)
Other investing activities	1,422	(218)
Net cash provided by (used in) investing activities	252,404	(171,628)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from non-recourse property debt	0	360,613
Principal repayments of non-recourse property debt	(19,580)	(206,262)
Net (repayments of) borrowings on revolving credit facility	(90,360)	11,475
Repurchases of Common Stock	(20,682)	0
Payment of dividends to holders of Preferred Stock	(4,082)	(4,085)
Payment of distributions to noncontrolling interests	0	(7,228)
Payment of distributions to General Partner and Special Limited Partner	(67,405)	(59,652)
Payment of distributions to Limited Partners	(3,767)	(2,737)
Redemptions of noncontrolling interests in the Aimco Operating Partnership	(2,653)	(7,122)
Purchases and redemptions of noncontrolling interests	0	(1,219)
Other financing activities	(302)	(3,012)
Net cash (used in) provided by financing activities	(208,227)	86,795
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	125,794	(3,510)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT BEGINNING OF PERIOD	72,595	142,541
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT END OF PERIOD	$ 198,389	$ 139,031

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Distributions in Excess of Earnings	Total Aimco Equity	Common Noncontrolling interests in Aimco Operating Partnerships	Noncontrolling interests in consolidated real estate partnerships
Balances (in shares) at Dec. 31, 2017		5,000	152,435
Balances at Dec. 31, 2017	$ 1,655,753	$ 125,000	$ 1,524	$ 3,900,090	$ 3,603	$ (2,367,073)	$ 1,663,144	$ (5,675)	$ (1,716)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of Aimco Operating Partnership Units	(6,963)							(6,963)
Amortization of share-based compensation cost (in shares)			19
Amortization of share-based compensation cost	2,988			2,631			2,631	357
Effect in changes in ownership for consolidated entities	(10,907)			(17,486)			(17,486)	6,579
Change in accumulated other comprehensive income	(62)				(59)		(59)	(3)
Other, net (in shares)			114
Other, net	93		$ 1	92			93
Net income	93,753					83,792	83,792	3,755	6,206
Distributions to noncontrolling interests	(7,245)								(7,245)
Cash dividends paid to Common Stock holders	(62,615)					(59,777)	(59,777)	(2,838)
Cash dividends paid to Preferred Stock holders	(2,148)					(2,148)	(2,148)
Balances (in shares) at Mar. 31, 2018		5,000	152,568
Balances at Mar. 31, 2018	1,662,647	$ 125,000	$ 1,525	3,885,327	3,544	(2,345,206)	1,670,190	(4,788)	(2,755)
Balances (in shares) at Dec. 31, 2018		5,000	144,623
Balances at Dec. 31, 2018	1,763,641	$ 125,000	$ 1,446	3,515,686	4,794	(1,947,507)	1,699,419	67,189	(2,967)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchases of Common Stock (in shares)			(461)
Repurchases of Common Stock	(20,682)		$ (5)	(20,677)			(20,682)
Redemption of Aimco Operating Partnership Units	(2,557)							(2,557)
Amortization of share-based compensation cost (in shares)			22
Amortization of share-based compensation cost	3,238			2,442			2,442	796
Effect in changes in ownership for consolidated entities				(2,168)			(2,168)	2,168
Change in accumulated other comprehensive income	61				57		57	4
Other, net (in shares)			82
Other, net	78		$ 2	57			59		19
Net income	289,361					274,133	274,133	15,137	91
Distributions to noncontrolling interests	(3,244)							(3,244)
Cash dividends paid to Common Stock holders	(67,476)					(67,476)	(67,476)
Common Stock issued in special dividend (n shares)			4,492
Common Stock issued in special dividend			$ 45	(45)
Cash dividends paid to Preferred Stock holders	(2,148)					(2,148)	(2,148)
Balances (in shares) at Mar. 31, 2019		5,000	148,758
Balances at Mar. 31, 2019	$ 1,960,272	$ 125,000	$ 1,488	$ 3,495,295	$ 4,851	$ (1,742,998)	$ 1,883,636	$ 79,493	$ (2,857)

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Partners’ Capital - USD ($) $ in Thousands	Total	AIMCO Properties, LP [Member]	AIMCO Properties, LP [Member]Preferred Units [Member]	AIMCO Properties, LP [Member]General Partner and Special Limited Partner [Member]	AIMCO Properties, LP [Member]Limited Partner [Member]	AIMCO Properties, LP [Member]Partners Capital Attributable To The Partnership [Member]	AIMCO Properties, LP [Member]Noncontrolling Interest [Member]
Balances at Dec. 31, 2017		$ 1,655,753	$ 125,000	$ 1,538,144	$ (5,675)	$ 1,657,469	$ (1,716)
Increase (Decrease) in Partners' Capital [Roll Forward]
Redemption of partnership units held by non-Aimco partners		(6,963)			(6,963)	(6,963)
Amortization of share-based compensation		2,988		2,631	357	2,988
Effect of changes in ownership for consolidated entities		10,907		17,486	(6,579)	10,907
Change in accumulated other comprehensive income	$ (62)	(62)		(59)	(3)	(62)
Other, net		93		93		93
Net income		93,753		83,792	3,755	87,547	6,206
Distributions to noncontrolling interests	(7,245)	(7,245)					(7,245)
Distributions to common unitholders		(62,615)		(59,777)	(2,838)	(62,615)
Distributions to preferred unitholders		(2,148)		(2,148)		(2,148)
Balances at Mar. 31, 2018		1,662,647	125,000	1,545,190	(4,788)	1,665,402	(2,755)
Balances at Dec. 31, 2018		1,763,641	125,000	1,574,419	67,189	1,766,608	(2,967)
Increase (Decrease) in Partners' Capital [Roll Forward]
Repurchases of common partnership units		(20,682)		(20,682)		(20,682)
Redemption of partnership units held by non-Aimco partners		(2,557)			(2,557)	(2,557)
Amortization of share-based compensation		3,238		2,442	796	3,238
Effect of changes in ownership for consolidated entities				(2,168)	2,168
Change in accumulated other comprehensive income	61	61		57	4	61
Other, net		78		59		59	19
Net income		289,361		274,133	15,137	289,270	91
Distributions to noncontrolling interests	$ (3,244)
Distributions to common unitholders		(70,720)		(67,476)	(3,244)	(70,720)
Distributions to preferred unitholders		(2,148)		(2,148)		(2,148)
Balances at Mar. 31, 2019		$ 1,960,272	$ 125,000	$ 1,758,636	$ 79,493	$ 1,963,129	$ (2,857)

Organization

Organization	3 Months Ended
	Mar. 31, 2019
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 some 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 March 31, 2019 , after eliminations for units held by consolidated subsidiaries, the Aimco Operating Partnership had 158,435,979 common partnership units outstanding. As of March 31, 2019 , Aimco owned 148,758,031 of the common partnership units ( 93.9% 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 March 31, 2019 , we owned an equity interest in 128 apartment communities with 34,349 apartment homes in our portfolio. Our 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 124 of these apartment communities with 34,207 apartment homes and these communities comprise our segments.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies 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 months ended March 31, 2019 , are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 . The balance sheets of Aimco and the Aimco Operating Partnership at December 31, 2018 , 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, 2018 . Except where indicated, the footnotes refer to both Aimco and the Aimco Operating Partnership. 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 9 ). 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 following table presents a reconciliation of the Aimco Operating Partnership’s preferred OP Units from December 31, 2018 to March 31, 2019 . The preferred OP Units may be redeemed at the holders’ option (as further discussed in Note 6 ), 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, 2018 $ 101,291 Distributions to holders of preferred OP Units (1,934 ) Redemption of preferred OP Units and other (96 ) Net income attributable to preferred OP Units 1,934 Balance, March 31, 2019 $ 101,195 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. Reclassifications and Revisions Certain items in the 2018 condensed consolidated financial statements have been reclassified to conform to the current presentation. We have also reclassified gain on dispositions of real estate and related income taxes, which were previously reported net on our condensed consolidated statements of operations, to now present gain on dispositions of real estate as a component of income before income taxes in our condensed consolidated statements of operations, as follows (in thousands): March 31, 2018 As Previously Reported Adjustments As Revised Income tax benefit $ 37,388 $ (2,871 ) $ 34,517 Gain on dispositions of real estate 50,324 2,871 53,195 During the three months ended March 31, 2019, Aimco and the Aimco Operating Partnership effected a reverse split of share of common shares and common partnership units, respectively, at a ratio of 1 share or unit for every 1.03119 shares or units outstanding on the date of effectiveness. The accounting guidance for recapitalization events requires that we revise Aimco’s equity and the Aimco Operating Partnership’s partners’ capital as if the reverse split had occurred at the beginning of the earliest period presented. As such, we have revised the outstanding share and unit counts, presentation of share and unit activity, and earnings per share and unit, as if the reverse split had occurred on December 31, 2017. Accounting Pronouncements Adopted in the Current Year Effective January 1, 2019, we adopted the lease accounting standard issued by the Financial Accounting Standards Board, or FASB. We elected to adopt the new standard using practical expedients that: do not require a look back to expired or existing contracts for embedded leases; allow us to retain the classification of existing leases; and allow us to retain the previous accounting for the initial direct costs of existing leases. Under the new standard, a contract is or contains a lease when it provides the right to control the use of an asset for a period of time in exchange for consideration. Lessor accounting remains largely unchanged. In our position as a lessor, we have elected the practical expedient that allows us to combine revenue attributable to nonlease components with associated lease components where the timing and pattern of transfer of the components are the same. As a result, we will combine rent payments with payments for other services we provide to our residents, including residents’ reimbursement of utility expenses. We have adopted the standard using the optional transition method that allows for prior reporting periods to remain as originally presented. Please refer to Note 4 . 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. The amendments created a requirement to report changes in equity and dividends per share in interim periods on a comparative basis for both quarter-to-date and year-to-date periods presented. We have presented comparative interim statements of stockholders’ and partners’ equity in our condensed consolidated financial statements for the three months ended March 31, 2019 and 2018 . Recent Accounting Pronouncements In June 2016, the FASB issued a new standard for accounting for financial instruments and credit losses thereon, which changes the method and timing of the recognition of credit losses on financial assets. The standard will require us to estimate and record credit losses over the life of a receivable at its inception. We have limited loans receivable and we invest in debt securities, which are subject to the new standard. Receivables related to operating leases are excluded from the new standard as they are subject to the lease accounting standard. This standard is required to be applied using a modified-retrospective approach and requires a cumulative-effect adjustment to retained earnings be recorded as of the date of adoption. The new standard is effective for us on January 1, 2020. We are currently in the process of completing our analysis of the impact of the standard and do not expect it to have a material effect on our financial position or results of operations.

Significant Transactions, Dispo

Significant Transactions, Dispositions of Apartment Communities and Assets Held for Sale	3 Months Ended
	Mar. 31, 2019
Discontinued Operations and Disposal Groups [Abstract]
Disposals and Other Significant Transactions	Significant Transactions Dispositions of Apartment Communities During the three months ended March 31, 2019 , we sold apartment communities as summarized below (dollars in thousands): Apartment communities sold 7 Apartment homes sold 2,206 Gain on dispositions of real estate $ 291,473 The apartment communities sold were predominantly located outside of our primary markets or in lower-rated locations within our primary markets, and had average revenues per apartment home significantly below those of our retained portfolio. In addition to the apartment communities we sold during the current period, 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 March 31, 2019 , no apartment communities were classified as held for sale.

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Leases	Leases The majority of payments that we receive for our residential and commercial leases are fixed. We receive variable payments from our residents and commercial tenants primarily for utility and other expense reimbursements. For the three months ended March 31, 2019 , our total lease income was comprised of the following amounts for all operating leases (in thousands): Fixed lease income $ 215,581 Variable lease income 14,144 Total lease income $ 229,725 In general, our leases have options to extend for a certain period of time at the lessee’s option. Future minimum annual rental payments we will receive under commercial operating leases are as follows (in thousands). We do not include our residential operating leases due to their shorter duration. April 1, 2019 to December 31, 2019 $ 13,431 2020 16,103 2021 13,736 2022 13,246 2023 12,394 Thereafter 57,942 Total $ 126,852 Beginning in 2019, we are required to recognize right of use assets and related lease liabilities on our consolidated balance sheets when we are the lessee. Upon adoption of the standard, we recognized right of use assets of $87.5 million , which is presented in the Other assets line item on our condensed consolidated balance sheets, net of accumulated amortization. We also recognized the related lease liabilities of $79.7 million , which are presented in the Accrued liabilities and other line item on our condensed consolidated balance sheets. We estimated the value of the lease liabilities using a discount rate equivalent to an incremental borrowing rate, or the rate Aimco would pay on a secured borrowing with similar terms to the lease, based on Aimco’s borrowing profile and the term of the underlying lease. Substantially all of the payments under our ground and office leases are fixed. Rents for extension periods, when provided for in the lease, are generally determined based on a fair value factor at the time the option is exercised; therefore, these extension periods are not included in our determination of the right of use asset and lease liability. For the three months ended March 31, 2019 , our total lease cost for ground and office leases was $3.2 million and $0.7 million , respectively. The ground and office leases have weighted average remaining terms of 79.4 years and 9.5 years , respectively, and weighted average discount rates of 4.12% and 3.65% , respectively. Minimum annual rental payments under operating leases, reconciled to the lease liabilities recognized on our condensed consolidated balance sheets are as follows (in thousands): Office Lease Obligations Ground Lease Obligations Total Operating Lease Obligations April 1, 2019 to December 31, 2019 $ 1,957 $ 1,586 $ 3,543 2020 2,806 2,350 5,156 2021 2,704 2,439 5,143 2022 2,561 2,492 5,053 2023 1,871 2,492 4,363 Thereafter 10,644 422,169 432,813 Total $ 22,543 $ 433,528 $ 456,071 Less: Discount (17,891 ) (357,386 ) Total lease liability $ 4,652 $ 76,142
Leases	Leases The majority of payments that we receive for our residential and commercial leases are fixed. We receive variable payments from our residents and commercial tenants primarily for utility and other expense reimbursements. For the three months ended March 31, 2019 , our total lease income was comprised of the following amounts for all operating leases (in thousands): Fixed lease income $ 215,581 Variable lease income 14,144 Total lease income $ 229,725 In general, our leases have options to extend for a certain period of time at the lessee’s option. Future minimum annual rental payments we will receive under commercial operating leases are as follows (in thousands). We do not include our residential operating leases due to their shorter duration. April 1, 2019 to December 31, 2019 $ 13,431 2020 16,103 2021 13,736 2022 13,246 2023 12,394 Thereafter 57,942 Total $ 126,852 Beginning in 2019, we are required to recognize right of use assets and related lease liabilities on our consolidated balance sheets when we are the lessee. Upon adoption of the standard, we recognized right of use assets of $87.5 million , which is presented in the Other assets line item on our condensed consolidated balance sheets, net of accumulated amortization. We also recognized the related lease liabilities of $79.7 million , which are presented in the Accrued liabilities and other line item on our condensed consolidated balance sheets. We estimated the value of the lease liabilities using a discount rate equivalent to an incremental borrowing rate, or the rate Aimco would pay on a secured borrowing with similar terms to the lease, based on Aimco’s borrowing profile and the term of the underlying lease. Substantially all of the payments under our ground and office leases are fixed. Rents for extension periods, when provided for in the lease, are generally determined based on a fair value factor at the time the option is exercised; therefore, these extension periods are not included in our determination of the right of use asset and lease liability. For the three months ended March 31, 2019 , our total lease cost for ground and office leases was $3.2 million and $0.7 million , respectively. The ground and office leases have weighted average remaining terms of 79.4 years and 9.5 years , respectively, and weighted average discount rates of 4.12% and 3.65% , respectively. Minimum annual rental payments under operating leases, reconciled to the lease liabilities recognized on our condensed consolidated balance sheets are as follows (in thousands): Office Lease Obligations Ground Lease Obligations Total Operating Lease Obligations April 1, 2019 to December 31, 2019 $ 1,957 $ 1,586 $ 3,543 2020 2,806 2,350 5,156 2021 2,704 2,439 5,143 2022 2,561 2,492 5,053 2023 1,871 2,492 4,363 Thereafter 10,644 422,169 432,813 Total $ 22,543 $ 433,528 $ 456,071 Less: Discount (17,891 ) (357,386 ) Total lease liability $ 4,652 $ 76,142

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
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 March 31, 2019 , our commitments related to these capital activities totaled approximately $184.7 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. 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 near 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 undertook a voluntary remediation of the dry cleaner contamination under IDEM’s oversight. 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 a contingent liability stemming from a property in Lake Tahoe, California, regarding environmental contamination 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 March 31, 2019 , are immaterial to our consolidated financial condition, results of operations and cash flows.

Earnings per Share_Unit

Earnings per Share/Unit	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings per Share/Unit	Earnings and Dividends 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 shares of Common Stock and common partnership units outstanding equal to the number of shares that vest. The dilutive effect of these securities was 0.2 million and 0.1 million shares and 0.3 million and 0.1 million units for the three months ended March 31, 2019 and 2018 , respectively. Securities with dilutive effect are included in the denominator for calculating diluted earnings per share and per unit during these periods. There were no shares and 0.2 million potential shares, and 0.4 million 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 months ended March 31, 2019 and 2018 . 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 0.2 million and 0.3 million unvested restricted participating shares and 0.2 million and 0.3 million unvested restricted participating units, for the three months ended March 31, 2019 and 2018 , 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 March 31, 2019 , these preferred OP Units were potentially redeemable for approximately 2.0 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. During the three months ended March 31, 2019 and 2018 , we paid $2.02 and $0.38 , respectively, in dividends and distributions per share and per unit. The $2.02 paid during the three months ended March 31, 2019 represents the per share and unit value of the special dividend and special distribution. The special dividend consisted of $67.1 million in cash, 4.5 million shares of Common Stock and $0.4 million of cash in paid lieu of issuing fractional shares. The special distribution consisted of $72.7 million in cash, 4.8 million common partnership units and $0.4 million of cash paid in lieu of issuing fractional units.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
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. These investments are included in 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. These investments were acquired at a discount to face value and we are accreting the discount to the $100.9 million face value of the investments through interest income using the effective interest method over the remaining expected term of the investments, which, as of March 31, 2019 , was approximately 2.2 years. Our amortized cost basis for these investments, which represents the original cost adjusted for interest accretion less interest payments received, was $85.1 million and $83.6 million at March 31, 2019 and December 31, 2018 , respectively. We estimated the fair value of these investments to be $90.1 million and $88.5 million at March 31, 2019 and December 31, 2018 , respectively. Our investments in AFS debt securities are classified within Level 2 of the GAAP fair value hierarchy. 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. Fair Value Disclosures We believe that the carrying value of the consolidated amounts of cash and cash equivalents, receivables and payables approximated their fair value at March 31, 2019 , and December 31, 2018 , due to their relatively short-term nature and high probability of realization. The carrying amounts of longer term seller financing notes receivable approximated their estimated fair value at March 31, 2019 and December 31, 2018 . The carrying amount of our total indebtedness approximated its estimated fair value at March 31, 2019 and December 31, 2018 . We estimate the fair value of our seller financing notes and 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 and seller financing notes 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	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Business Segments	Business Segments During the three months ended March 31, 2019, as a result of the 2018 sale of the Asset Management business, we revised the information regularly reviewed by our chief executive officer, who is our chief operating decision maker, to assess our operating performance. We have determined we have four segments: Same Store, Redevelopment and Development, Acquisition, and Other Real Estate. Our Same Store segment includes communities that have reached a stabilized level of operations as of the beginning of a two-year comparable period and maintained it throughout the current and comparable prior year, and are not expected to be sold within 12 months. Our Redevelopment and Development segment includes apartment communities that are currently under construction that have not achieved a stabilized level of operations, and those that have been completed in recent years that have not achieved and maintained stabilized operations for both the current and comparable prior year. Our Acquisition segment includes apartment communities that we have acquired since the beginning of a two-year comparable period. Our Other Real Estate segment primarily includes apartment communities that are subject to limitations on rent increases and communities that we expect to sell within 12 months but do not yet meet the criteria to be classified as held for sale. 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 for consolidated apartment communities. We exclude from rental and other property revenues the amount of utility costs 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. As of March 31, 2019 , our Same-Store segment included 96 consolidated apartment communities with 28,039 apartment homes; our Redevelopment and Development segment included seven consolidated apartment communities with 3,373 apartment homes; our Acquisition segment included six consolidated apartment communities with 1,480 apartment homes; and our Other Real Estate segment included 15 apartment communities with 1,315 apartment homes. The following tables present the revenues, proportionate property net operating income and income before income tax (expense) benefit of our segments on a proportionate basis and excluding our proportionate share of four communities with 142 apartment homes, which we do not consolidate, and amounts related to apartment communities sold as of March 31, 2019 for the three months ended March 31, 2019 and 2018 (in thousands): Same Store Redevelopment and Development Acquisition Other Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Segments (2) Consolidated Three months ended March 31, 2019: Total revenues $ 175,719 $ 20,350 $ 9,993 $ 9,467 $ 8,747 $ 5,959 $ 230,235 Property operating expenses attributable to real estate 47,137 7,290 2,855 3,883 8,189 9,830 79,184 Other operating expenses not allocated to segments (3) — — — — — 109,637 109,637 Total operating expenses 47,137 7,290 2,855 3,883 8,189 119,467 188,821 Proportionate property net operating income 128,582 13,060 7,138 5,584 558 (113,508 ) 41,414 Other items included in income before income tax expense (4) — — — — — 252,862 252,862 Income before income tax expense $ 128,582 $ 13,060 $ 7,138 $ 5,584 $ 558 $ 139,354 $ 294,276 Same Store Redevelopment and Development Acquisition Other Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Segments (2) Consolidated Three months ended March 31, 2018: Rental and other property revenues attributable to real estate $ 168,606 $ 18,077 $ 1,580 $ 9,312 $ 8,236 $ 19,582 $ 225,393 Asset Management business rental and tax credit revenues — — — — — 22,327 22,327 Total revenues 168,606 18,077 1,580 9,312 8,236 41,909 247,720 Property operating expenses attributable to real estate 46,755 6,499 523 3,839 7,726 12,945 78,287 Property operating expenses of partnerships served by Asset Management business — — — — — 9,195 9,195 Other operating expenses not allocated to segments (3) — — — — — 106,861 106,861 Total operating expenses 46,755 6,499 523 3,839 7,726 129,001 194,343 Proportionate property net operating income 121,851 11,578 1,057 5,473 510 (87,092 ) 53,377 Other items included in income before income tax benefit (4) — — — — — 7,796 7,796 Income before income tax benefit $ 121,851 $ 11,578 $ 1,057 $ 5,473 $ 510 $ (79,296 ) $ 61,173 (1) Represents adjustments for the noncontrolling interests in consolidated real estate partnerships’ share of the results of consolidated apartment communities in our segments, 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 Segments 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 segments 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 income tax (expense) benefit primarily consists of gain on dispositions of real estate and interest expense. The assets of our segments and the consolidated assets not allocated to our segments were as follows (in thousands): March 31, 2019 December 31, 2018 Same Store $ 4,148,435 $ 4,148,787 Redevelopment and Development 822,348 792,126 Acquisition 546,467 507,190 Other Real Estate 326,241 327,099 Corporate and other assets (1) 440,278 414,802 Total consolidated assets $ 6,283,769 $ 6,190,004 (1) Includes the assets not allocated to our segments, primarily corporate assets and assets of apartment communities sold as of March 31, 2019 . For the three months ended March 31, 2019 and 2018 , capital additions related to our segments were as follows (in thousands): Three Months Ended March 31, 2019 2018 Same Store $ 30,211 $ 27,522 Redevelopment and Development 39,048 43,481 Acquisition 3,868 483 Other Real Estate 2,771 2,141 Total capital additions $ 75,898 $ 73,627

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2019
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 the Aimco Operating Partnership consolidates own interests in one or more apartment communities and are typically structured to generate a return for their partners through the operation and ultimate sale of the communities. The Aimco Operating Partnership is the primary beneficiary in the limited partnerships in which it is the sole decision maker and has a substantial economic interest. The table below summarizes information regarding VIEs consolidated by the Aimco Operating Partnership: March 31, 2019 December 31, 2018 VIEs with interests in apartment communities 9 9 Apartment communities owned by VIEs 9 9 Apartment homes in communities owned by VIEs 3,592 3,592 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): March 31, 2019 December 31, 2018 Assets Net real estate $ 494,193 $ 488,127 Cash and cash equivalents 17,508 15,416 Restricted cash 4,868 4,461 Other assets 28,500 3,973 Liabilities Non-recourse property debt secured by Aimco communities, net 320,995 322,685 Accrued liabilities and other 39,639 13,576

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
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 months ended March 31, 2019 , are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 . The balance sheets of Aimco and the Aimco Operating Partnership at December 31, 2018 , 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, 2018 . 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 9 ). 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 6 ), 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 and Recent Accounting Pronouncements	Accounting Pronouncements Adopted in the Current Year Effective January 1, 2019, we adopted the lease accounting standard issued by the Financial Accounting Standards Board, or FASB. We elected to adopt the new standard using practical expedients that: do not require a look back to expired or existing contracts for embedded leases; allow us to retain the classification of existing leases; and allow us to retain the previous accounting for the initial direct costs of existing leases. Under the new standard, a contract is or contains a lease when it provides the right to control the use of an asset for a period of time in exchange for consideration. Lessor accounting remains largely unchanged. In our position as a lessor, we have elected the practical expedient that allows us to combine revenue attributable to nonlease components with associated lease components where the timing and pattern of transfer of the components are the same. As a result, we will combine rent payments with payments for other services we provide to our residents, including residents’ reimbursement of utility expenses. We have adopted the standard using the optional transition method that allows for prior reporting periods to remain as originally presented. Please refer to Note 4 . 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. The amendments created a requirement to report changes in equity and dividends per share in interim periods on a comparative basis for both quarter-to-date and year-to-date periods presented. We have presented comparative interim statements of stockholders’ and partners’ equity in our condensed consolidated financial statements for the three months ended March 31, 2019 and 2018 . Recent Accounting Pronouncements In June 2016, the FASB issued a new standard for accounting for financial instruments and credit losses thereon, which changes the method and timing of the recognition of credit losses on financial assets. The standard will require us to estimate and record credit losses over the life of a receivable at its inception. We have limited loans receivable and we invest in debt securities, which are subject to the new standard. Receivables related to operating leases are excluded from the new standard as they are subject to the lease accounting standard. This standard is required to be applied using a modified-retrospective approach and requires a cumulative-effect adjustment to retained earnings be recorded as of the date of adoption. The new standard is effective for us on January 1, 2020. We are currently in the process of completing our analysis of the impact of the standard and do not expect it to have a material effect on our financial position or results of operations.

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2019
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, 2018 to March 31, 2019 . The preferred OP Units may be redeemed at the holders’ option (as further discussed in Note 6 ), 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, 2018 $ 101,291 Distributions to holders of preferred OP Units (1,934 ) Redemption of preferred OP Units and other (96 ) Net income attributable to preferred OP Units 1,934 Balance, March 31, 2019 $ 101,195
Reclassifications to conform to the current presentation	We have also reclassified gain on dispositions of real estate and related income taxes, which were previously reported net on our condensed consolidated statements of operations, to now present gain on dispositions of real estate as a component of income before income taxes in our condensed consolidated statements of operations, as follows (in thousands): March 31, 2018 As Previously Reported Adjustments As Revised Income tax benefit $ 37,388 $ (2,871 ) $ 34,517 Gain on dispositions of real estate 50,324 2,871 53,195

Significant Transactions, Dis_2

Significant Transactions, Dispositions of Apartment Communities and Assets Held for Sale Disposal Groups, Including Discontinued Operations (Tables)	3 Months Ended
	Mar. 31, 2019
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations [Table Text Block]	During the three months ended March 31, 2019 , we sold apartment communities as summarized below (dollars in thousands): Apartment communities sold 7 Apartment homes sold 2,206 Gain on dispositions of real estate $ 291,473

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Lease income for operating leases	For the three months ended March 31, 2019 , our total lease income was comprised of the following amounts for all operating leases (in thousands): Fixed lease income $ 215,581 Variable lease income 14,144 Total lease income $ 229,725
Future minimum annual rental payments receivable under commercial operating leases	Future minimum annual rental payments we will receive under commercial operating leases are as follows (in thousands). We do not include our residential operating leases due to their shorter duration. April 1, 2019 to December 31, 2019 $ 13,431 2020 16,103 2021 13,736 2022 13,246 2023 12,394 Thereafter 57,942 Total $ 126,852
Minimum annual rental payments under operating leases	Minimum annual rental payments under operating leases, reconciled to the lease liabilities recognized on our condensed consolidated balance sheets are as follows (in thousands): Office Lease Obligations Ground Lease Obligations Total Operating Lease Obligations April 1, 2019 to December 31, 2019 $ 1,957 $ 1,586 $ 3,543 2020 2,806 2,350 5,156 2021 2,704 2,439 5,143 2022 2,561 2,492 5,053 2023 1,871 2,492 4,363 Thereafter 10,644 422,169 432,813 Total $ 22,543 $ 433,528 $ 456,071 Less: Discount (17,891 ) (357,386 ) Total lease liability $ 4,652 $ 76,142

Business Segments (Tables)

Business Segments (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Summary information for the reportable segments	The following tables present the revenues, proportionate property net operating income and income before income tax (expense) benefit of our segments on a proportionate basis and excluding our proportionate share of four communities with 142 apartment homes, which we do not consolidate, and amounts related to apartment communities sold as of March 31, 2019 for the three months ended March 31, 2019 and 2018 (in thousands): Same Store Redevelopment and Development Acquisition Other Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Segments (2) Consolidated Three months ended March 31, 2019: Total revenues $ 175,719 $ 20,350 $ 9,993 $ 9,467 $ 8,747 $ 5,959 $ 230,235 Property operating expenses attributable to real estate 47,137 7,290 2,855 3,883 8,189 9,830 79,184 Other operating expenses not allocated to segments (3) — — — — — 109,637 109,637 Total operating expenses 47,137 7,290 2,855 3,883 8,189 119,467 188,821 Proportionate property net operating income 128,582 13,060 7,138 5,584 558 (113,508 ) 41,414 Other items included in income before income tax expense (4) — — — — — 252,862 252,862 Income before income tax expense $ 128,582 $ 13,060 $ 7,138 $ 5,584 $ 558 $ 139,354 $ 294,276 Same Store Redevelopment and Development Acquisition Other Real Estate Proportionate and Other Adjustments (1) Corporate and Amounts Not Allocated to Segments (2) Consolidated Three months ended March 31, 2018: Rental and other property revenues attributable to real estate $ 168,606 $ 18,077 $ 1,580 $ 9,312 $ 8,236 $ 19,582 $ 225,393 Asset Management business rental and tax credit revenues — — — — — 22,327 22,327 Total revenues 168,606 18,077 1,580 9,312 8,236 41,909 247,720 Property operating expenses attributable to real estate 46,755 6,499 523 3,839 7,726 12,945 78,287 Property operating expenses of partnerships served by Asset Management business — — — — — 9,195 9,195 Other operating expenses not allocated to segments (3) — — — — — 106,861 106,861 Total operating expenses 46,755 6,499 523 3,839 7,726 129,001 194,343 Proportionate property net operating income 121,851 11,578 1,057 5,473 510 (87,092 ) 53,377 Other items included in income before income tax benefit (4) — — — — — 7,796 7,796 Income before income tax benefit $ 121,851 $ 11,578 $ 1,057 $ 5,473 $ 510 $ (79,296 ) $ 61,173 (1) Represents adjustments for the noncontrolling interests in consolidated real estate partnerships’ share of the results of consolidated apartment communities in our segments, 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 Segments 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 segments consists of depreciation and amortization, general and administrative expenses and other operating expenses, which are not included in our measure of segment performance. (4)
Reconciliation of Assets from Segment to Consolidated [Table Text Block]	The assets of our segments and the consolidated assets not allocated to our segments were as follows (in thousands): March 31, 2019 December 31, 2018 Same Store $ 4,148,435 $ 4,148,787 Redevelopment and Development 822,348 792,126 Acquisition 546,467 507,190 Other Real Estate 326,241 327,099 Corporate and other assets (1) 440,278 414,802 Total consolidated assets $ 6,283,769 $ 6,190,004 (1) Includes the assets not allocated to our segments, primarily corporate assets and assets of apartment communities sold as of March 31, 2019 .
Capital additions related to segments	For the three months ended March 31, 2019 and 2018 , capital additions related to our segments were as follows (in thousands): Three Months Ended March 31, 2019 2018 Same Store $ 30,211 $ 27,522 Redevelopment and Development 39,048 43,481 Acquisition 3,868 483 Other Real Estate 2,771 2,141 Total capital additions $ 75,898 $ 73,627

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 2019
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: March 31, 2019 December 31, 2018 VIEs with interests in apartment communities 9 9 Apartment communities owned by VIEs 9 9 Apartment homes in communities owned by VIEs 3,592 3,592 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): March 31, 2019 December 31, 2018 Assets Net real estate $ 494,193 $ 488,127 Cash and cash equivalents 17,508 15,416 Restricted cash 4,868 4,461 Other assets 28,500 3,973 Liabilities Non-recourse property debt secured by Aimco communities, net 320,995 322,685 Accrued liabilities and other 39,639 13,576

Organization (Details Textual)

Organization (Details Textual)	3 Months Ended
	Mar. 31, 2019apartment_homePropertyshares
Organization [Line Items]
Common partnership units and equivalents outstanding | shares	148,758,031
Percentage of the Aimco Operating Partnership's common partnership units and equivalents owned by Aimco	93.90%
Partially Owned Properties [Member]
Organization [Line Items]
Number of apartment communities | Property	128
Number of apartment homes in apartment communities | apartment_home	34,349
Wholly And Partially Owned Consolidated Properties [Member]
Organization [Line Items]
Number of apartment communities | Property	124
Number of apartment homes in apartment communities | apartment_home	34,207
AIMCO PROPERTIES, L.P [Member]
Organization [Line Items]
Common partnership units and equivalents outstanding | shares	158,435,979

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 198,389	$ 72,595	$ 139,031	$ 142,541

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance, December 31, 2018	$ 101,291
Balance, March 31, 2019	101,195
AIMCO PROPERTIES, L.P [Member]
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance, December 31, 2018	101,291
Distributions to holders of preferred OP Units	(1,934)
Redemption of preferred OP Units and other	(96)
Net income attributable to preferred OP Units	1,934
Balance, March 31, 2019	$ 101,195

Basis of Presentation and Sum_6

Basis of Presentation and Summary of Significant Accounting Policies (Details 1) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income tax benefit	$ (2,981)	$ 34,517
Gain on dispositions of real estate	$ 291,473	53,195
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income tax benefit		37,388
Gain on dispositions of real estate		50,324
Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income tax benefit		(2,871)
Gain on dispositions of real estate		$ 2,871

Significant Transactions, Dis_3

Significant Transactions, Dispositions of Apartment Communities and Assets Held for Sale (Details Textual)	3 Months Ended
	Mar. 31, 2019USD ($)apartment_homeProperty	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest in Limited Partnerships	$ (2,857,000)		$ (2,967,000)
Gain (loss) on dispositions of real estate and the Asset Management business, inclusive of related income tax	291,473,000	$ 53,195,000
Assets	6,283,769,000		6,190,004,000
Liabilities	4,222,302,000		$ 4,325,072,000
Gain (Loss) on Sale of Properties, before Applicable Income Taxes	$ 291,473,000	$ 53,195,000
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 | apartment_home	34,207
Number of apartment communities | Property	124
Disposal Group, Disposed of by Sale, Not Discontinued Operations [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 | apartment_home	2,206
Number of apartment communities | Property	7
Gain (Loss) on Sale of Properties, before Applicable Income Taxes	$ 291,473

Leases - Lease Income for Opera

Leases - Lease Income for Operating Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Leases [Abstract]
Fixed lease income	$ 215,581
Variable lease income	14,144
Total lease income	$ 229,725

Leases - Future Minimum Annual

Leases - Future Minimum Annual Payments Receivable Under Commercial Operating Leases (Details) $ in Thousands	Mar. 31, 2019USD ($)
Leases [Abstract]
April 1, 2019 to December 31, 2019	$ 13,431
2020	16,103
2021	13,736
2022	13,246
2023	12,394
Thereafter	57,942
Total	$ 126,852

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019
Ground Lease
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Weighted Average Discount Rate, Percent	4.12%
Lease liabilities	$ 76,142
Lease cost	$ 3,200
Weighted average remaining term	79 years 5 months
Office Lease
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Weighted Average Discount Rate, Percent	3.65%
Lease liabilities	$ 4,652
Lease cost	$ 700
Weighted average remaining term	9 years 6 months
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use assets		$ 87,500
Lease liabilities		$ 79,700

Leases - Minimum Annual Rental

Leases - Minimum Annual Rental Payments Under Operating Leases (Details) $ in Thousands	Mar. 31, 2019USD ($)
Lessee, Lease, Description [Line Items]
April 1, 2019 to December 31, 2019	$ 3,543
2020	5,156
2021	5,143
2022	5,053
2023	4,363
Thereafter	432,813
Total	456,071
Office Lease Obligations
Lessee, Lease, Description [Line Items]
April 1, 2019 to December 31, 2019	1,957
2020	2,806
2021	2,704
2022	2,561
2023	1,871
Thereafter	10,644
Total	22,543
Less: Discount	(17,891)
Total lease liability	4,652
Ground Lease Obligations
Lessee, Lease, Description [Line Items]
April 1, 2019 to December 31, 2019	1,586
2020	2,350
2021	2,439
2022	2,492
2023	2,492
Thereafter	422,169
Total	433,528
Less: Discount	(357,386)
Total lease liability	$ 76,142

Commitments and Contingencies (

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

Earnings per Share_Unit (Detail

Earnings per Share/Unit (Details Textual) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Schedule of Earnings Per Share and Dividends Per Share [Line Items]
Dilutive potential common shares/units (in shares)	0.2	0.1
Antidilutive securities excluded from the denominator for calculating dilutive earnings per share and per unit (in shares)	0	0.2
Participating securities outstanding (in shares)	0.2	0.3
Preferred noncontrolling interests in Aimco Operating Partnership	$ 101,195,000		$ 101,291,000
Number of shares potentially redeemable for (in shares)	2
Dividends	$ 2.02
Dividends paid (in dollars per share)		$ 0.38
Special dividend	$ 67,476,000	$ 62,615,000
Distributions paid (in dollars per share)	$ 2.02000000	$ 0.38000000
AIMCO Properties, LP [Member]
Schedule of Earnings Per Share and Dividends Per Share [Line Items]
Dilutive potential common shares/units (in shares)	0.3	0.1
Antidilutive securities excluded from the denominator for calculating dilutive earnings per share and per unit (in shares)	0.4	0.2
Participating securities outstanding (in shares)		0.3
Preferred noncontrolling interests in Aimco Operating Partnership	$ 101,195,000		$ 101,291,000
Special distribution	70,720,000	$ 62,615,000
AIMCO Properties, LP [Member] | General Partner and Special Limited Partner [Member]
Schedule of Earnings Per Share and Dividends Per Share [Line Items]
Special distribution	67,476,000	$ 59,777,000
Special Cash Distribution [Member] | AIMCO Properties, LP [Member] | General Partner and Special Limited Partner [Member]
Schedule of Earnings Per Share and Dividends Per Share [Line Items]
Special distribution	72,700,000
Special distribution, cash paid in lieu of fractional shares	$ 400,000
Units issued in special dividend (in shares)	4.8
Special Dividend Paid [Member]
Schedule of Earnings Per Share and Dividends Per Share [Line Items]
Special dividend	$ 67,100,000
Special dividend, cash paid in lieu of fractional shares	$ 400,000
Common shares issued in special dividend (in shares)	4.5

Fair Value Measurements (Detail

Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total indebtedness associated with Real Estate portfolio	$ 3,929,023	$ 4,075,665
Non-recourse property debt, net	3,859,023	3,915,305
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 2 months
Amortized cost of the investment in available-for-sale debt securities	$ 85,100	83,600
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	$ 90,100	$ 88,500

Business Segments (Details Text

Business Segments (Details Textual) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)apartment_homePropertyUnitsSegment	Mar. 31, 2018USD ($)	Dec. 31, 2018PropertyUnits
Business Segments (Textual) [Abstract]
Number of reportable segments | Segment	4
Capital additions related to segments | $	$ 75,898	$ 73,627
Operating Segments [Member] | Same Store [Member]
Business Segments (Textual) [Abstract]
Capital additions related to segments | $	30,211	27,522
Operating Segments [Member] | Redevelopment and Development [Member]
Business Segments (Textual) [Abstract]
Capital additions related to segments | $	39,048	43,481
Operating Segments [Member] | Acquisition [Member]
Business Segments (Textual) [Abstract]
Capital additions related to segments | $	3,868	483
Operating Segments [Member] | Other Real Estate [Member]
Business Segments (Textual) [Abstract]
Capital additions related to segments | $	$ 2,771	$ 2,141
Partially Owned Properties [Member]
Business Segments (Textual) [Abstract]
Number of owned and managed apartment communities in segments | Property	128
Number of apartment homes in apartment communities	34,349
Wholly And Partially Owned Consolidated Properties [Member]
Business Segments (Textual) [Abstract]
Number of owned and managed apartment communities in segments | Property	124
Number of apartment homes in apartment communities	34,207
Wholly And Partially Owned Consolidated Properties [Member] | Same Store [Member]
Business Segments (Textual) [Abstract]
Number of owned and managed apartment communities in segments	96
Number of apartment homes in apartment communities	28,039
Wholly And Partially Owned Consolidated Properties [Member] | Redevelopment and Development [Member]
Business Segments (Textual) [Abstract]
Number of owned and managed apartment communities in segments	7
Number of apartment homes in apartment communities	3,373
Wholly And Partially Owned Consolidated Properties [Member] | Acquisition [Member]
Business Segments (Textual) [Abstract]
Number of owned and managed apartment communities in segments	6
Number of apartment homes in apartment communities	1,480
Wholly And Partially Owned Consolidated Properties [Member] | Other Real Estate [Member]
Business Segments (Textual) [Abstract]
Number of owned and managed apartment communities in segments	15
Number of apartment homes in apartment communities	1,315
Variable Interest Entity, Primary Beneficiary [Member]
Business Segments (Textual) [Abstract]
Number of owned and managed apartment communities in segments | Property	9		9
Number of apartment homes in apartment communities | Units	3,592		3,592

Business Segments (Details)

Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Summary information for the reportable segments
Rental and other property revenues	$ 230,235	$ 225,393
Tax credit and transaction revenues	0	22,327
Total revenues	230,235	247,720
Property operating expenses	79,184	78,287
Direct Costs of Leased and Rented Property or Equipment - Asset Management	0	9,195
Depreciation and amortization	93,565	92,548
General and administrative expenses	10,369	11,355
Other operating expenses not allocated to reportable segment (3)	109,637	106,861
Total operating expenses	188,821	194,343
Operating Income (Loss), Property	41,414	53,377
Other Items included in income before gain on dispositions (4)	252,862	7,796
Income before gain (loss) on dispositions	294,276	61,173
Segment Reconciling Items [Member]
Summary information for the reportable segments
Rental and other property revenues		8,236
Total revenues	8,747	8,236
Property operating expenses	8,189	7,726
Total operating expenses	8,189	7,726
Operating Income (Loss), Property	558	510
Income before gain (loss) on dispositions	558	510
Corporate Non-Segment [Member]
Summary information for the reportable segments
Rental and other property revenues		19,582
Tax credit and transaction revenues		22,327
Total revenues	5,959	41,909
Property operating expenses	9,830	12,945
Direct Costs of Leased and Rented Property or Equipment - Asset Management		9,195
Other operating expenses not allocated to reportable segment (3)	109,637	106,861
Total operating expenses	119,467	129,001
Operating Income (Loss), Property	(113,508)	(87,092)
Other Items included in income before gain on dispositions (4)	252,862	7,796
Income before gain (loss) on dispositions	139,354	(79,296)
Same Store [Member] | Operating Segments [Member]
Summary information for the reportable segments
Rental and other property revenues		168,606
Tax credit and transaction revenues		0
Total revenues	175,719	168,606
Property operating expenses	47,137	46,755
Direct Costs of Leased and Rented Property or Equipment - Asset Management		0
Total operating expenses	47,137	46,755
Operating Income (Loss), Property	128,582	121,851
Income before gain (loss) on dispositions	128,582	121,851
Redevelopment and Development [Member] | Operating Segments [Member]
Summary information for the reportable segments
Rental and other property revenues		18,077
Tax credit and transaction revenues		0
Total revenues	20,350	18,077
Property operating expenses	7,290	6,499
Direct Costs of Leased and Rented Property or Equipment - Asset Management		0
Total operating expenses	7,290	6,499
Operating Income (Loss), Property	13,060	11,578
Income before gain (loss) on dispositions	13,060	11,578
Acquisition [Member] | Operating Segments [Member]
Summary information for the reportable segments
Rental and other property revenues		1,580
Tax credit and transaction revenues		0
Total revenues	9,993	1,580
Property operating expenses	2,855	523
Direct Costs of Leased and Rented Property or Equipment - Asset Management		0
Total operating expenses	2,855	523
Operating Income (Loss), Property	7,138	1,057
Income before gain (loss) on dispositions	7,138	1,057
Other Real Estate [Member] | Operating Segments [Member]
Summary information for the reportable segments
Rental and other property revenues		9,312
Tax credit and transaction revenues		0
Total revenues	9,467	9,312
Property operating expenses	3,883	3,839
Direct Costs of Leased and Rented Property or Equipment - Asset Management		0
Total operating expenses	3,883	3,839
Operating Income (Loss), Property	5,584	5,473
Income before gain (loss) on dispositions	$ 5,584	$ 5,473

Business Segments (Details 1)

Business Segments (Details 1) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total assets	$ 6,283,769	$ 6,190,004
Corporate Non-Segment [Member]
Segment Reporting Information [Line Items]
Total assets	440,278	414,802
Same Store [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	4,148,435	4,148,787
Redevelopment and Development [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	822,348	792,126
Acquisition [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	546,467	507,190
Other Real Estate [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total assets	$ 326,241	$ 327,099

Business Segments (Details 2)

Business Segments (Details 2) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Capital additions	$ 75,898	$ 73,627
Same Store [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Capital additions	30,211	27,522
Redevelopment and Development [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Capital additions	39,048	43,481
Acquisition [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Capital additions	3,868	483
Other Real Estate [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Capital additions	$ 2,771	$ 2,141

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Thousands	Mar. 31, 2019USD ($)PropertyUnitsEntity	Dec. 31, 2018USD ($)PropertyUnitsEntity
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Net real estate	$ 5,643,853	$ 5,723,475
Cash and cash equivalents	162,286	36,858
Restricted cash	36,103	35,737
Assets held for sale	0	42,393
Other Assets	441,527	351,541
Non-recourse property debt secured by Aimco communities, net	3,859,023	3,915,305
Accrued liabilities and other	293,279	226,230
Liabilities related to assets held for sale	$ 0	$ 23,177
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Number of consolidated variable interest entities | Entity	9	9
Number of apartment communities | Property	9	9
Number of apartment homes owned by VIEs | Units	3,592	3,592
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Net real estate	$ 494,193	$ 488,127
Cash and cash equivalents	17,508	15,416
Restricted cash	4,868	4,461
Other Assets	28,500	3,973
Non-recourse property debt secured by Aimco communities, net	320,995	322,685
Accrued liabilities and other	$ 39,639	$ 13,576