Cover - USD ($)	12 Months Ended
	Dec. 31, 2020	Jan. 31, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-11312
Entity Registrant Name	COUSINS PROPERTIES INC
Entity Incorporation, State or Country Code	GA
Entity Tax Identification Number	58-0869052
Entity Address, Address Line One	3344 Peachtree Road NE
Entity Address, Address Line Two	Suite 1800
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30326-4802
City Area Code	(404)
Local Phone Number	407-1000
Title of 12(b) Security	Common Stock ($1 par value)
Trading Symbol	CUZ
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 4,460,913,956
Entity Common Stock, Shares Outstanding		148,566,470
Documents Incorporated by Reference	Portions of the Registrant’s proxy statement for the annual stockholders meeting to be held on April 27, 2021 are incorporated by reference into Part III of this Form 10-K.
Entity Central Index Key	0000025232
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false