Restatement of Previously Issued Consolidated Financial Statements - Schedule of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended							6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Condensed Statement of Income Captions [Line Items]
Net income (loss)												$ 26,030	$ (65,718)	$ 23,234
Other comprehensive loss:
Unrealized gain (loss) on valuation of swap agreements												30,500	(73,686)	(35,883)
Reclassification of realized interest on swap agreements												(21,407)	(15,059)	870
Other comprehensive income (loss)												51,907	(58,627)	(36,753)
Comprehensive (loss) income												77,937	(124,345)	(13,519)
Comprehensive income (loss) attributable to Acadia												$ 62,225	(52,393)	21,727
Previously Reported
Condensed Statement of Income Captions [Line Items]
Net income (loss)	$ 31,557	$ 1,231	$ 1,860	$ (32,616)	$ (38,289)	$ 64,906	$ (60,039)	$ 3,091	$ 4,867	$ 34,648	$ (33,422)		(66,038)	21,204
Other comprehensive loss:
Unrealized gain (loss) on valuation of swap agreements	1,045	(10,073)	33,556		952	(8,621)	(74,774)	23,483	(83,395)	24,528	(82,444)		(74,236)	(35,674)
Reclassification of realized interest on swap agreements	5,528	5,324	5,317		5,506	3,115	977	10,641	4,092	16,169	9,598		15,203	(872)
Other comprehensive income (loss)	6,573	(4,749)	38,873		6,458	(5,506)	(73,797)	34,124	(79,303)	40,697	(72,846)		(59,033)	(36,546)
Comprehensive (loss) income	38,130	(3,518)	40,733		(31,831)	59,400	(133,836)	37,215	(74,436)	75,345	(106,268)		(125,071)	(15,342)
Comprehensive loss attributable to noncontrolling interests	(21,321)	1,489	(2,642)		27,137	(44,484)	70,882	(1,153)	26,398	(22,474)	53,536		72,596	36,696
Comprehensive income (loss) attributable to Acadia	16,809	(2,029)	38,091		(4,694)	14,916	(62,954)	36,062	(48,038)	52,871	(52,732)		(52,475)	21,354
Adjustments
Condensed Statement of Income Captions [Line Items]
Net income (loss)	(485)	(779)	(1,163)	(309)	446	(2,101)	2,284	(1,942)	183	(2,427)	629		320	2,030
Other comprehensive loss:
Unrealized gain (loss) on valuation of swap agreements	3	4	0		(3)	312	239	4	551	7	548		550	(209)
Reclassification of realized interest on swap agreements	(52)	(52)	(49)		(50)	(30)	(15)	(101)	(45)	(153)	(95)		(144)	2
Other comprehensive income (loss)	(49)	(48)	(49)		(53)	282	224	(97)	506	(146)	453		406	(207)
Comprehensive (loss) income	(534)	(827)	(1,212)		393	(1,819)	2,508	(2,039)	689	(2,573)	1,082		726	1,823
Comprehensive loss attributable to noncontrolling interests	472	620	867		(398)	2,034		1,487	(465)	1,959	(863)		(644)	(1,450)
Comprehensive income (loss) attributable to Acadia	(62)	(207)	(345)		(5)	215	9	(552)	224	(614)	219		82	373
As Restated
Condensed Statement of Income Captions [Line Items]
Net income (loss)	31,072	452	697	$ (32,925)	(37,843)	62,805	(57,755)	1,149	5,050	32,221	(32,793)		(65,718)	23,234
Other comprehensive loss:
Unrealized gain (loss) on valuation of swap agreements	1,048	(10,069)	33,556		949	(8,309)	(74,535)	23,487	(82,844)	24,535	(81,896)		(73,686)	(35,883)
Reclassification of realized interest on swap agreements	5,476	5,272	5,268		5,456	3,085	962	10,540	4,047	16,016	9,503		15,059	(870)
Other comprehensive income (loss)	6,524	(4,797)	38,824		6,405	(5,224)	(73,573)	34,027	(78,797)	40,551	(72,393)		(58,627)	(36,753)
Comprehensive (loss) income	37,596	(4,345)	39,521		(31,438)	57,581	(131,328)	35,176	(73,747)	72,772	(105,186)		(124,345)	(13,519)
Comprehensive loss attributable to noncontrolling interests	(20,849)	2,109	(1,775)		26,739	(42,450)	68,383	334	25,933	(20,515)	52,673		71,952	35,246
Comprehensive income (loss) attributable to Acadia	$ 16,747	$ (2,236)	$ 37,746		$ (4,699)	$ 15,131	$ (62,945)	$ 35,510	$ (47,814)	$ 52,257	$ (52,513)		$ (52,393)	$ 21,727