Segment Reporting - Summary of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Total Revenues	$ 74,660	$ 63,773	$ 144,054	$ 135,193
Depreciation and amortization	(31,345)	(33,793)	(62,735)	(67,170)
Property operating expenses, other operating and real estate taxes	(25,394)	(27,503)	(50,333)	(51,270)
General and administrative expenses	(10,671)	(8,720)	(19,667)	(17,790)
Impairment charges	0	0	0	(51,549)
Gain on disposition of properties	5,909	485	10,521	485
Operating income (loss)	13,159	(5,758)	21,840	(52,101)
Interest income	2,054	2,095	3,754	5,024
Realized and unrealized holding gains on investments and other	2,711	87,811	9,218	87,281
Equity in earnings (losses) of unconsolidated affiliates	1,106	(786)	3,369	469
Interest expense	(17,605)	(18,319)	(34,746)	(36,621)
Income tax (provision) benefit	(194)	(137)	(344)	815
Net (loss) income	1,231	64,906	3,091	4,867
Net loss (income) attributable to noncontrolling interests	2,687	(45,496)	5,989	6,129
Net (loss) income attributable to Acadia	3,918	19,410	9,080	10,996
Real estate at cost	4,043,253	4,162,224	4,043,253	4,162,224
Total assets	4,089,612	4,328,748	4,089,612	4,328,748	$ 4,186,882
Cash paid for acquisition of real estate			0	21,208
Cash paid for development and property improvement costs			16,620	20,533
Operating Segments | Core Portfolio
Segment Reporting Information [Line Items]
Total Revenues	46,000	38,602	88,350	78,535
Depreciation and amortization	(17,333)	(18,150)	(34,220)	(35,207)
Property operating expenses, other operating and real estate taxes	(14,205)	(17,961)	(27,862)	(29,775)
General and administrative expenses	0	0	0	0
Impairment charges				0
Gain on disposition of properties	0	0	4,612	0
Operating income (loss)	14,462	2,491	30,880	13,553
Interest income	0	0	0	0
Realized and unrealized holding gains on investments and other	0	0	0	0
Equity in earnings (losses) of unconsolidated affiliates	669	(1,070)	(459)	572
Interest expense	(7,350)	(8,602)	(14,564)	(16,852)
Income tax (provision) benefit	0	0	0	0
Net (loss) income	7,781	(7,181)	15,857	(2,727)
Net loss (income) attributable to noncontrolling interests	(406)	5,068	(1,013)	6,284
Net (loss) income attributable to Acadia	7,375	(2,113)	14,844	3,557
Real estate at cost	2,323,767	2,362,334	2,323,767	2,362,334
Total assets	2,209,033	2,323,986	2,209,033	2,323,986
Cash paid for acquisition of real estate			0	19,963
Cash paid for development and property improvement costs			5,465	6,443
Operating Segments | Opportunity Funds
Segment Reporting Information [Line Items]
Total Revenues	28,660	25,171	55,704	56,658
Depreciation and amortization	(14,012)	(15,643)	(28,515)	(31,963)
Property operating expenses, other operating and real estate taxes	(11,189)	(9,542)	(22,471)	(21,495)
General and administrative expenses	0	0	0	0
Impairment charges				(51,549)
Gain on disposition of properties	5,909	485	5,909	485
Operating income (loss)	9,368	471	10,627	(47,864)
Interest income	0	0	0	0
Realized and unrealized holding gains on investments and other	2,841	87,751	9,388	87,751
Equity in earnings (losses) of unconsolidated affiliates	437	284	3,828	(103)
Interest expense	(10,255)	(9,717)	(20,182)	(19,769)
Income tax (provision) benefit	0	0	0	0
Net (loss) income	2,391	78,789	3,661	20,015
Net loss (income) attributable to noncontrolling interests	3,093	(50,564)	7,002	(155)
Net (loss) income attributable to Acadia	5,484	28,225	10,663	19,860
Real estate at cost	1,719,486	1,799,890	1,719,486	1,799,890
Total assets	1,763,299	1,870,070	1,763,299	1,870,070
Cash paid for acquisition of real estate			0	1,245
Cash paid for development and property improvement costs			11,155	14,090
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	0	0
Operating income (loss)	0	0	0	0
Interest income	2,054	2,095	3,754	5,024
Realized and unrealized holding gains on investments and other	(130)	60	(170)	(470)
Equity in earnings (losses) of unconsolidated affiliates	0	0	0	0
Interest expense	0	0	0	0
Income tax (provision) benefit	0	0	0	0
Net (loss) income	1,924	2,155	3,584	4,554
Net loss (income) attributable to noncontrolling interests	0	0	0	0
Net (loss) income attributable to Acadia	1,924	2,155	3,584	4,554
Real estate at cost	0	0	0	0
Total assets	117,280	134,692	117,280	134,692
Cash paid for acquisition of real estate			0	0
Cash paid for development and property improvement costs			0	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	(10,671)	(8,720)	(19,667)	(17,790)
Impairment charges				0
Gain on disposition of properties	0	0	0	0
Operating income (loss)	(10,671)	(8,720)	(19,667)	(17,790)
Interest income	0	0	0	0
Realized and unrealized holding gains on investments and other	0	0	0	0
Equity in earnings (losses) of unconsolidated affiliates	0	0	0	0
Interest expense	0	0	0	0
Income tax (provision) benefit	(194)	(137)	(344)	815
Net (loss) income	(10,865)	(8,857)	(20,011)	(16,975)
Net loss (income) attributable to noncontrolling interests	0	0	0	0
Net (loss) income attributable to Acadia	(10,865)	(8,857)	(20,011)	(16,975)
Real estate at cost	0	0	0	0
Total assets	$ 0	$ 0	0	0
Cash paid for acquisition of real estate			0	0
Cash paid for development and property improvement costs			$ 0	$ 0