(Loss) Earnings Per Common Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net (loss) income attributable to Acadia	$ (8,759)	$ 53,045	$ 31,439
Less: net income attributable to participating securities	(233)	(413)	(267)
(Loss) income from continuing operations net of income attributable to participating securities	$ (8,992)	$ 52,632	$ 31,172
Denominator:
Weighted average shares for basic earnings per share (in shares)	86,441,922	84,435,826	82,080,159
Effect of dilutive securities:
Employee unvested restricted shares (in shares)	0	0	0
Denominator for diluted earnings per share (in shares)	86,441,922	84,435,826	82,080,159
Basic (loss) income and diluted earnings per Common Share from continuing operations attributable to Acadia	$ (0.10)	$ 0.62	$ 0.38
Series A Preferred OP Units
Anti-Dilutive Shares Excluded from Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	188	188	188
Series A Preferred OP Units - Common Share Equivalent
Anti-Dilutive Shares Excluded from Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	25,067	25,067	25,067
Series C Preferred OP Units
Anti-Dilutive Shares Excluded from Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	126,593	136,593	136,593
Series C Preferred OP Units - Common Share Equivalent
Anti-Dilutive Shares Excluded from Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	439,556	474,278	474,278
Restricted shares
Anti-Dilutive Shares Excluded from Denominator:
Antidilutive securities excluded from computation of earnings per share (in shares)	76,394	40,821	36,879