Other Significant Transactions (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Schedule of Financial Position Related to Legally Sold Portfolio [Line Items]
Real estate, net	$ 5,580,271	$ 5,472,779
Cash and cash equivalents	45,241	28,971	$ 29,186	$ 55,751
Other assets	478,961	476,727
Total assets	6,217,662	6,097,028
Total indebtedness	3,935,899	4,135,139
Accrued and other liabilities	324,746	279,077
Total liabilities	4,380,961	4,566,986
Noncontrolling interests in consolidated real estate partnerships	164,439	233,296
Equity attributable to Aimco and the Aimco Operating Partnership	(17,365)	(18,926)
Total liabilities and equity/partners' capital	6,217,662	6,097,028
Napico Portfolio [Member]
Schedule of Financial Position Related to Legally Sold Portfolio [Line Items]
Noncontrolling interests in consolidated real estate partnerships	697	44,106
Equity attributable to Aimco and the Aimco Operating Partnership	4,324	(1,029)
Total liabilities and equity/partners' capital	158,307	161,135
Napico Portfolio [Member] | Other Assets [Member]
Schedule of Financial Position Related to Legally Sold Portfolio [Line Items]
Real estate, net	107,407	117,851
Cash and cash equivalents	33,715	23,133
Investment in unconsolidated real estate partnerships	766	8,392
Other assets	16,419	11,759
Total assets	158,307	161,135
Napico Portfolio [Member] | Accrued liabilities and other [Member]
Schedule of Financial Position Related to Legally Sold Portfolio [Line Items]
Total indebtedness	143,987	113,641
Accrued and other liabilities	9,299	4,417
Total liabilities	$ 153,286	$ 118,058