Organization and Description of Business - Narrative (Details)	12 Months Ended
	Dec. 31, 2019 Bed Property
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of properties	167
Number of beds | Bed	112,800
Minimum
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Initial terms of contract	1 year
Maximum
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Initial terms of contract	5 years
Management and leasing services
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of properties	36
Number of beds | Bed	26,500
Owned & third-party managed portfolio
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of properties	203
Number of beds | Bed	139,300
Off campus properties | Owned Properties
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of properties	127
American campus equity | Owned Properties
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of properties	34
Under development | Owned Properties
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of beds | Bed	11,300
Number of properties under construction	3
On-campus participating properties, net
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of properties	6
AMERICAN CAMPUS COMMUNITIES OPERATING PARTNERSHIP LP
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Limited partner ownership interest (percent)	99.60%
AMERICAN CAMPUS COMMUNITIES OPERATING PARTNERSHIP LP | Maximum
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Ownership interest (percent)	1.00%