Segment Reporting (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) segment	Jun. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			3
Revenues	$ 59,504	$ 43,918	$ 121,503	$ 91,963
Depreciation and amortization	(26,057)	(14,678)	(50,593)	(31,527)
Property operating expenses, other operating and real estate taxes	(17,841)	(11,283)	(36,938)	(23,276)
General and administrative expenses	(8,864)	(8,521)	(17,333)	(17,873)
Operating income	6,742	9,436	16,639	19,287
Gain on disposition of properties	0	16,572	0	81,965
Interest income	8,203	7,415	17,187	12,053
Equity in earnings of unconsolidated affiliates	4,340	1,740	17,043	3,694
Interest expense	(12,750)	(8,897)	(24,238)	(16,935)
Income tax provision	(427)	(111)	(552)	(34)
Net income	6,108	26,155	26,079	100,030
Net loss (income) attributable to noncontrolling interests	5,952	(8,237)	1,612	(53,187)
Net income attributable to Acadia	12,060	17,918	27,691	46,843
Real estate at cost	3,486,007	2,647,745	3,486,007	2,647,745
Total assets	4,048,845	3,235,040	4,048,845	3,235,040
Acquisition of real estate	43,097	6,250	77,785	18,537
Development and property improvement costs	19,288	18,427	46,303	55,890
Core Portfolio
Segment Reporting Information [Line Items]
Revenues	41,488	34,693	85,933	72,800
Depreciation and amortization	(15,534)	(11,706)	(31,973)	(25,201)
Property operating expenses, other operating and real estate taxes	(10,160)	(8,286)	(23,012)	(16,848)
General and administrative expenses	0	0	0	0
Operating income	15,794	14,701	30,948	30,751
Gain on disposition of properties		0		0
Interest income	0	0	0	0
Equity in earnings of unconsolidated affiliates	982	581	1,542	1,173
Interest expense	(6,933)	(7,113)	(14,088)	(13,877)
Income tax provision	0	0	0	0
Net income	9,843	8,169	18,402	18,047
Net loss (income) attributable to noncontrolling interests	(372)	(9)	(804)	(2,831)
Net income attributable to Acadia	9,471	8,160	17,598	15,216
Real estate at cost	1,984,601	1,528,848	1,984,601	1,528,848
Total assets	2,252,390	1,809,395	2,252,390	1,809,395
Acquisition of real estate	0	6,250	0	6,250
Development and property improvement costs	2,758	6,975	3,753	10,222
Funds
Segment Reporting Information [Line Items]
Revenues	18,016	9,225	35,570	19,163
Depreciation and amortization	(10,523)	(2,972)	(18,620)	(6,326)
Property operating expenses, other operating and real estate taxes	(7,681)	(2,997)	(13,926)	(6,428)
General and administrative expenses	0	0	0	0
Operating income	(188)	3,256	3,024	6,409
Gain on disposition of properties		16,572		81,965
Interest income	0	0	0	0
Equity in earnings of unconsolidated affiliates	3,358	1,159	15,501	2,521
Interest expense	(5,817)	(1,784)	(10,150)	(3,058)
Income tax provision	0	0	0	0
Net income	(2,647)	19,203	8,375	87,837
Net loss (income) attributable to noncontrolling interests	6,324	(8,228)	2,416	(50,356)
Net income attributable to Acadia	3,677	10,975	10,791	37,481
Real estate at cost	1,501,406	1,118,897	1,501,406	1,118,897
Total assets	1,546,607	1,152,103	1,546,607	1,152,103
Acquisition of real estate	43,097	0	77,785	12,287
Development and property improvement costs	16,530	11,452	42,550	45,668
Structured Financing
Segment Reporting Information [Line Items]
Revenues		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
Operating income	0	0	0	0
Gain on disposition of properties		0		0
Interest income	8,203	7,415	17,187	12,053
Equity in earnings of unconsolidated affiliates	0	0	0	0
Interest expense	0	0	0	0
Income tax provision	0	0	0	0
Net income	8,203	7,415	17,187	12,053
Net loss (income) attributable to noncontrolling interests	0	0	0	0
Net income attributable to Acadia	8,203	7,415	17,187	12,053
Real estate at cost	0	0	0	0
Total assets	249,848	273,542	249,848	273,542
Acquisition of real estate	0	0	0	0
Development and property improvement costs	0	0	0	0
Unallocated
Segment Reporting Information [Line Items]
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	(8,864)	(8,521)	(17,333)	(17,873)
Operating income	(8,864)	(8,521)	(17,333)	(17,873)
Gain on disposition of properties		0		0
Interest income	0	0	0	0
Equity in earnings of unconsolidated affiliates	0	0	0	0
Interest expense	0	0	0	0
Income tax provision	(427)	(111)	(552)	(34)
Net income	(9,291)	(8,632)	(17,885)	(17,907)
Net loss (income) attributable to noncontrolling interests	0	0	0	0
Net income attributable to Acadia	(9,291)	(8,632)	(17,885)	(17,907)
Real estate at cost	0	0	0	0
Total assets	0	0	0	0
Acquisition of real estate	0	0	0	0
Development and property improvement costs	$ 0	$ 0	$ 0	$ 0