Variable Interest Entities (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended					12 Months Ended
	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2011 Variable Interest Entity, Not Primarily Beneficiary Held Through Consolidated Tax Credit Funds in Which Company Holds Substantially All Economic Interests [Member]	Dec. 31, 2011 Receivables From Unconsolidated Variable Interest Entities [Member]	Dec. 31, 2011 Obligation to Advance Funds to Unconsolidated Variable Interest Entities [Member]	Dec. 31, 2010 Newly Consolidated from New Accounting Principle [Member] Property	Dec. 31, 2010 Deconsolidated from New Accounting Principle [Member] Property	Dec. 31, 2010 Maximum [Member] Newly Consolidated from New Accounting Principle [Member]	Dec. 31, 2010 Minimum [Member] Newly Consolidated from New Accounting Principle [Member]	Dec. 31, 2010 Average [Member] Newly Consolidated from New Accounting Principle [Member]	Dec. 31, 2011 Variable Interest Entity, Primary Beneficiary [Member] Entity Property	Dec. 31, 2010 Variable Interest Entity, Primary Beneficiary [Member] Newly Consolidated from New Accounting Principle [Member] Entity	Dec. 31, 2011 Variable Interest Entity, Not Primary Beneficiary [Member] Entity Property
Variable Interest Entity [Line Items]
Number of variable interest entities consolidated											120	49
Number of variable interest entities unconsolidated													201
Number of apartment properties owned by consolidated variable interest entities											82	31
Number of apartment properties owned by unconsolidated variable interest entities													254
Number of units in apartment properties owned by consolidated variable interest entities											12,888
Number of units in apartment properties owned by unconsolidated variable interest entities													14,190
Number of properties owned by consolidated variable interest entities							10
Number of partnerships and properties consolidated at fair value						13
Net reduction of Aimco equity from adoption of ASU 2009-17	$ 27.7					$ 30.7	$ (3.0)
Charge to equity attributed to additional losses or deficit distribution	30.7
Carrying value of real estate collateralizing debt of consolidated VIEs											794.7
Carrying value of property debt of consolidated VIEs											638.5
Investments in unconsolidated VIEs through consolidated VIEs in which we hold an insignificant economic interest													24.0
Ownership interest in variable interest entities							55.00%	35.00%	1.00%	7.00%
General partner or equivalent interest in consolidated tax credit funds that are VIEs and that own an interest in unconsolidated VIEs													1% or less
Basis Of Presentation [Line Items]
Maximum risk or loss related to investment in ,receivable from, or contractual obligation to advance funds to unconsolidated VIEs			5.3	96.7	3.0
Variable Interest Entities (Textual) [Abstract]
Maximum risk of loss on investments in unconsolidated VIEs through consolidated VIEs in which we hold substantially all the economic interests		5.3
Increase in total assets from adoption of ASU 2009-17	114.9
Increase in total liabilities from adoption of ASU 2009-17	91.7
Increase in noncontrolling interests from adoption of ASU 2009-17	$ 50.9