Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Numerator:
Net income attributable to Acadia	$ 15,631		$ 28,925
Less: net income attributable to participating securities	(162)		(365)
Income from continuing operations net of income attributable to participating securities	$ 15,469		$ 28,560
Denominator:
Weighted average shares for basic earnings per share	83,635,000		70,756,000
Effect of dilutive securities:
Employee share options	11,000		16,000
Convertible Preferred OP Units	0		428,000
Denominator for diluted earnings per share	83,646,000		71,200,000
Basic and diluted earnings per Common Share from continuing operations attributable to Acadia (in dollars per share)	$ 0.18		$ 0.40
Series A Preferred Stock [Member] | Common Shares
Schedule of Earnings Per Share, Basic and Diluted [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	25,067
Series C Preferred Stock [Member]
Schedule of Earnings Per Share, Basic and Diluted [Line Items]
Preferred OP Units (in shares)	141,593	141,593
Series C Preferred Stock [Member] | Common Shares
Schedule of Earnings Per Share, Basic and Diluted [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	471,035	403,054
Operating Partnership, as General Partner or Managing Member [Member]
Schedule of Earnings Per Share, Basic and Diluted [Line Items]
Preferred OP Units (in shares)	3,363,351	3,357,760
Operating Partnership, as General Partner or Managing Member [Member] | Series A Preferred Stock [Member]
Schedule of Earnings Per Share, Basic and Diluted [Line Items]
Preferred OP Units (in shares)	188	188
Operating Partnership, as General Partner or Managing Member [Member] | Series C Preferred Stock [Member]
Schedule of Earnings Per Share, Basic and Diluted [Line Items]
Preferred OP Units (in shares)	141,593	141,593