Segment Reporting - Summary of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Total Revenues	$ 73,446	$ 51,281	$ 217,500	$ 186,474
Depreciation and amortization	(30,866)	(34,457)	(93,601)	(101,627)
Property operating expenses, other operating and real estate taxes	(24,018)	(22,248)	(74,351)	(73,518)
General and administrative expenses	(9,978)	(8,625)	(29,645)	(26,415)
Impairment charges	(9,925)	0	(9,925)	(51,549)
Gain on disposition of properties	0	24	10,521	509
Operating income (loss)	(1,341)	(14,025)	20,499	(66,126)
Interest income	2,354	2,132	6,108	7,156
Realized and unrealized holding gains (losses) on investments and other	47,293	7,946	56,511	79,335
Equity in (losses) earnings of unconsolidated affiliates	644	(624)	4,013	(155)
Interest expense	(17,334)	(17,752)	(52,080)	(54,373)
Income tax (provision) benefit	(59)	(74)	(403)	741
Net income (loss)	31,557	(38,289)	34,648	(33,422)
Net (income) loss attributable to noncontrolling interests	(19,488)	29,259	(13,499)	35,388
Net (loss) income attributable to Acadia	12,069	(9,030)	21,149	1,966
Real estate at cost	4,135,328	4,168,291	4,135,328	4,168,291
Total assets	4,244,645	4,251,408	4,244,645	4,251,408	$ 4,186,882
Cash paid for acquisition of real estate			63,425	21,208
Cash paid for development and property improvement costs			27,197	27,949
Operating Segments | Core Portfolio
Segment Reporting Information [Line Items]
Total Revenues	45,942	38,848	134,292	117,383
Depreciation and amortization	(17,678)	(17,987)	(51,898)	(53,193)
Property operating expenses, other operating and real estate taxes	(13,911)	(12,709)	(41,773)	(42,484)
General and administrative expenses	0	0	0	0
Impairment charges				0
Gain on disposition of properties		0	4,612	0
Operating income (loss)	14,353	8,152	45,233	21,706
Interest income	0	0		0
Realized and unrealized holding gains (losses) on investments and other	0	0		0
Equity in (losses) earnings of unconsolidated affiliates	(485)	(784)	(944)	(212)
Interest expense	(7,446)	(8,276)	(22,010)	(25,127)
Income tax (provision) benefit	0	0		0
Net income (loss)	6,422	(908)	22,279	(3,633)
Net (income) loss attributable to noncontrolling interests	(906)	1,407	(1,919)	7,691
Net (loss) income attributable to Acadia	5,516	499	20,360	4,058
Real estate at cost	2,328,208	2,365,426	2,328,208	2,365,426
Total assets	2,201,871	2,291,730	2,201,871	2,291,730
Cash paid for acquisition of real estate				19,963
Cash paid for development and property improvement costs			11,601	7,522
Operating Segments | Opportunity Funds
Segment Reporting Information [Line Items]
Total Revenues	27,504	12,433	83,208	69,091
Depreciation and amortization	(13,188)	(16,470)	(41,703)	(48,434)
Property operating expenses, other operating and real estate taxes	(10,107)	(9,539)	(32,578)	(31,034)
General and administrative expenses	0	0	0	0
Impairment charges	(9,925)		(9,925)	(51,549)
Gain on disposition of properties		24	5,909	509
Operating income (loss)	(5,716)	(13,552)	4,911	(61,417)
Interest income	0	0		0
Realized and unrealized holding gains (losses) on investments and other	47,643	7,906	57,031	79,845
Equity in (losses) earnings of unconsolidated affiliates	1,129	160	4,957	57
Interest expense	(9,888)	(9,476)	(30,070)	(29,246)
Income tax (provision) benefit	0	0		0
Net income (loss)	33,168	(30,774)	36,829	(10,761)
Net (income) loss attributable to noncontrolling interests	(18,582)	27,852	(11,580)	27,697
Net (loss) income attributable to Acadia	14,586	(2,922)	25,249	16,936
Real estate at cost	1,807,120	1,802,865	1,807,120	1,802,865
Total assets	1,884,306	1,824,880	1,884,306	1,824,880
Cash paid for acquisition of real estate			63,425	1,245
Cash paid for development and property improvement costs			15,596	20,427
Operating Segments | Structured Financing
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Depreciation and amortization	0	0	0	0
Property operating expenses, other operating and real estate taxes	0	0	0	0
General and administrative expenses	0	0	0	0
Impairment charges				0
Gain on disposition of properties		0		0
Operating income (loss)	0	0		0
Interest income	2,354	2,132	6,108	7,156
Realized and unrealized holding gains (losses) on investments and other	(350)	(40)	(520)	(510)
Equity in (losses) earnings of unconsolidated affiliates	0	0		0
Interest expense	0	0		0
Income tax (provision) benefit	0	0		0
Net income (loss)	2,004	2,092	5,588	6,646
Net (income) loss attributable to noncontrolling interests	0	0		0
Net (loss) income attributable to Acadia	2,004	2,092	5,588	6,646
Real estate at cost		0		0
Total assets	158,468	134,798	158,468	134,798
Cash paid for acquisition of real estate				0
Cash paid for development and property improvement costs				0
Unallocated
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Depreciation and amortization	0	0	0	0
Property operating expenses, other operating and real estate taxes	0	0	0	0
General and administrative expenses	(9,978)	(8,625)	(29,645)	(26,415)
Impairment charges				0
Gain on disposition of properties		0		0
Operating income (loss)	(9,978)	(8,625)	(29,645)	(26,415)
Interest income	0	0		0
Realized and unrealized holding gains (losses) on investments and other	0	0		0
Equity in (losses) earnings of unconsolidated affiliates	0	0		0
Interest expense	0	0		0
Income tax (provision) benefit	(59)	(74)	(403)	741
Net income (loss)	(10,037)	(8,699)	(30,048)	(25,674)
Net (income) loss attributable to noncontrolling interests	0	0		0
Net (loss) income attributable to Acadia	(10,037)	(8,699)	(30,048)	(25,674)
Real estate at cost		0		0
Total assets		$ 0		0
Cash paid for acquisition of real estate				0
Cash paid for development and property improvement costs				$ 0