Commitments and Contingencies (Details)	1 Months Ended	3 Months Ended	12 Months Ended
	Aug. 31, 2013 USD ($) Contract	Sep. 30, 2017 USD ($) Property	Dec. 31, 2019 USD ($) Property	Dec. 31, 2017 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Number of properties, under development | Property			3
Alternate Housing Guarantees and Project Cost Guarantees
Commitments and Contingencies Disclosure [Line Items]
Project cost guarantees expiration (within years following project completion)			5 days
Project Cost Guarantees
Commitments and Contingencies Disclosure [Line Items]
Project cost guarantees expiration (within years following project completion)			1 year
Third-Party Development Projects [Member]
Commitments and Contingencies Disclosure [Line Items]
Commitment under third-party development project			$ 10,600,000
Performance guarantee
Commitments and Contingencies Disclosure [Line Items]
Project cost guarantees expiration (within years following project completion)			60 days
Estimate of possible loss			$ 614,600,000
Earnest Money Deposits			2,100,000
Purchase And Sale Agreement Upon Exercise Of Option			28,700,000
Drexel University Property
Commitments and Contingencies Disclosure [Line Items]
Lease term	40 years
Number of renewal options | Contract	3
Lease extension period	10 years
Commitment to pay real estate transfer taxes, amount	$ 1,800,000
Real estate transfer taxes paid upon conveyance of land	600,000
Maximum | Drexel University Property
Commitments and Contingencies Disclosure [Line Items]
Commitment to pay real estate transfer taxes, amount	$ 2,400,000
Construction Contracts
Commitments and Contingencies Disclosure [Line Items]
Construction contacts, amount to complete projects			446,400,000
AMERICAN CAMPUS COMMUNITIES OPERATING PARTNERSHIP LP | Core Transaction | Consolidated Properties
Commitments and Contingencies Disclosure [Line Items]
Number of operating properties purchased through joint venture arrangement | Property		2
Joint venture term		2 years
Core Transaction
Commitments and Contingencies Disclosure [Line Items]
Number of operating properties purchased through joint venture arrangement | Property		2
Asset acquisition, consideration transferred		$ 306,000,000.0	76,800,000	$ 144,300,000
Disney College Program Phases I-V (ACE) | Performance guarantee
Commitments and Contingencies Disclosure [Line Items]
Development guarantee, damages due per bed each day of a delay			20
Guarantee, maximum exposure			$ 200,000