Earnings Per Share - Summary of Elements Used in Calculating Basic and Diluted Earnings per Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator - basic and diluted earnings per unit
Net income									$ 86,762	$ 119,124	$ 70,121
Net income attributable to noncontrolling interests – partially owned properties	$ (1,128)	$ 887	$ 176	$ (1,728)	$ (2,117)	$ 392	$ 19	$ (323)	(1,793)	(2,029)	(1,083)
AMERICAN CAMPUS COMMUNITIES OPERATING PARTNERSHIP LP
Numerator - basic and diluted earnings per unit
Net income									86,762	119,124	70,121
Net income attributable to noncontrolling interests – partially owned properties	(1,030)	970	230	(1,568)	(1,880)	413	366	(114)	(1,398)	(1,215)
Series A preferred unit distributions	$ (14)	$ (14)	$ (9)	$ (31)	$ (31)	$ (31)	$ (31)	$ (31)	(68)	(124)	(124)
Amount allocated to participating securities									(1,902)	(1,522)	(1,536)
Net income attributable to common unitholders									$ 83,394	$ 116,263	$ 68,026
Denominator
Basic weighted average common units outstanding (units)									137,826,949	137,586,759	136,160,609
Unvested restricted stock awards (units)									990,941	906,998	860,962
Diluted weighted average common units outstanding (units)									138,817,890	138,493,757	137,021,571
Earnings per unit
Net income attributable to common unitholders - basic (in dollars per unit)									$ 0.61	$ 0.85	$ 0.50
Net income attributable to common unitholders - diluted (in dollars per unit)	$ 0.18	$ 0.14	$ 0.07	$ 0.21	$ 0.34	$ (0.02)	$ 0.33	$ 0.18	$ 0.60	$ 0.84	$ 0.50
Partially owned properties | AMERICAN CAMPUS COMMUNITIES OPERATING PARTNERSHIP LP
Numerator - basic and diluted earnings per unit
Net income attributable to noncontrolling interests – partially owned properties									$ (1,398)	$ (1,215)	$ (435)