Segment Reporting (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) segment	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment									3
Revenues	$ 54,121	$ 43,855	$ 43,918	$ 48,045	$ 51,286	$ 51,124	$ 49,176	$ 49,073	$ 189,939	$ 199,063	$ 179,681
Property operating expenses, other operating and real estate taxes									(57,391)	(58,482)	(51,671)
General and administrative expenses									(40,648)	(30,368)	(27,433)
Depreciation and amortization									(70,011)	(60,751)	(49,645)
Impairment of asset									0	(5,000)	0
Operating income									21,889	44,462	50,932
Equity in (losses) earnings of unconsolidated affiliates									39,449	37,330	111,578
Interest income									25,829	16,603	12,607
Other									0	1,596	2,724
Interest and other finance expense									(34,645)	(37,297)	(39,426)
Gain on disposition of properties									81,965	89,063	13,138
Income tax benefit (provision)									105	(1,787)	(629)
Income from continuing operations											150,924
Income from discontinued operations									0	0	1,222
Net income	34,236	326	26,155	73,875	7,871	18,104	85,458	38,537	134,592	149,970	152,146
Net (income) loss attributable to noncontrolling interests	(14,415)	$ 5,786	$ (8,237)	$ (44,950)	1,019	$ (4,328)	$ (58,963)	$ (21,990)	(61,816)	(84,262)	(81,082)
Net income attributable to Acadia									72,776	65,708	71,064
Real estate at cost	3,382,000				2,736,283				3,382,000	2,736,283	2,208,595
Total assets	3,995,960				3,032,319				3,995,960	3,032,319	2,720,721
Acquisition of real estate	495,644				338,700				495,644	338,700	256,453
Development and property improvement costs	149,434				164,315				149,434	164,315	140,118
Core Portfolio [Member]
Segment Reporting Information [Line Items]
Revenues									150,211	150,015	125,022
Property operating expenses, other operating and real estate taxes									(39,598)	(37,259)	(33,097)
General and administrative expenses									0	0	0
Depreciation and amortization									(54,582)	(46,223)	(35,875)
Impairment of asset										(5,000)
Operating income									56,031	61,533	56,050
Equity in (losses) earnings of unconsolidated affiliates									3,774	1,169	(77)
Interest income									0	0	0
Other										0	0
Interest and other finance expense									(27,435)	(27,945)	(27,024)
Gain on disposition of properties									0	0	12,577
Income tax benefit (provision)									0	0	0
Income from continuing operations											41,526
Income from discontinued operations											0
Net income									32,370	34,757	41,526
Net (income) loss attributable to noncontrolling interests									(3,411)	(140)	(3,222)
Net income attributable to Acadia									28,959	34,617	38,304
Real estate at cost	1,982,763				1,572,681				1,982,763	1,572,681	1,366,017
Total assets	2,271,620				1,662,092				2,271,620	1,662,092	1,613,290
Acquisition of real estate	323,880				181,884				323,880	181,884	206,203
Development and property improvement costs	13,434				16,505				13,434	16,505	5,432
Funds
Segment Reporting Information [Line Items]
Revenues									39,728	49,048	54,659
Property operating expenses, other operating and real estate taxes									(17,793)	(21,223)	(18,574)
General and administrative expenses									0	0	0
Depreciation and amortization									(15,429)	(14,528)	(13,770)
Impairment of asset										0
Operating income									6,506	13,297	22,315
Equity in (losses) earnings of unconsolidated affiliates									35,675	36,161	111,655
Interest income									0	0	0
Other										0	0
Interest and other finance expense									(7,210)	(9,352)	(12,402)
Gain on disposition of properties									81,965	89,063	561
Income tax benefit (provision)									0	0	0
Income from continuing operations											122,129
Income from discontinued operations											1,222
Net income									116,936	129,169	123,351
Net (income) loss attributable to noncontrolling interests									(58,405)	(84,122)	(77,860)
Net income attributable to Acadia									58,531	45,047	45,491
Real estate at cost	1,399,237				1,163,602				1,399,237	1,163,602	842,578
Total assets	1,448,177				1,223,039				1,448,177	1,223,039	1,005,145
Acquisition of real estate	171,764				156,816				171,764	156,816	50,250
Development and property improvement costs	136,000				147,810				136,000	147,810	134,686
Structuring Financing
Segment Reporting Information [Line Items]
Revenues									0	0	0
Property operating expenses, other operating and real estate taxes									0	0	0
General and administrative expenses									0	0	0
Depreciation and amortization									0	0	0
Impairment of asset										0
Operating income									0	0	0
Equity in (losses) earnings of unconsolidated affiliates									0	0	0
Interest income									25,829	16,603	12,607
Other										1,596	2,724
Interest and other finance expense									0	0	0
Gain on disposition of properties									0	0	0
Income tax benefit (provision)									0	0	0
Income from continuing operations											15,331
Income from discontinued operations											0
Net income									25,829	18,199	15,331
Net (income) loss attributable to noncontrolling interests									0	0	0
Net income attributable to Acadia									25,829	18,199	15,331
Real estate at cost	0				0				0	0	0
Total assets	276,163				147,188				276,163	147,188	102,286
Acquisition of real estate	0				0				0	0	0
Development and property improvement costs	0				0				0	0	0
Other
Segment Reporting Information [Line Items]
Revenues									0	0	0
Property operating expenses, other operating and real estate taxes									0	0	0
General and administrative expenses									(40,648)	(30,368)	(27,433)
Depreciation and amortization									0	0	0
Impairment of asset										0
Operating income									(40,648)	(30,368)	(27,433)
Equity in (losses) earnings of unconsolidated affiliates									0	0	0
Interest income									0	0	0
Other										0	0
Interest and other finance expense									0	0	0
Gain on disposition of properties									0	0	0
Income tax benefit (provision)									105	(1,787)	(629)
Income from continuing operations											(28,062)
Income from discontinued operations											0
Net income									(40,543)	(32,155)	(28,062)
Net (income) loss attributable to noncontrolling interests									0	0	0
Net income attributable to Acadia									(40,543)	(32,155)	(28,062)
Real estate at cost	0				0				0	0	0
Total assets	0				0				0	0	0
Acquisition of real estate	0				0				0	0	0
Development and property improvement costs	$ 0				$ 0				$ 0	$ 0	$ 0