Cover - USD ($)	12 Months Ended
	Dec. 31, 2021	Feb. 18, 2022	Jun. 30, 2021
Cover
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	000-54970
Entity Registrant Name	CORPORATE PROPERTY ASSOCIATES 18 – GLOBAL INCORPORATED
Entity Incorporation, State	MD
Entity Tax Identification Number	90-0885534
Entity Address, Street	One Manhattan West, 395 9th Avenue, 58th Floor
Entity Address, City	New York,
Entity Address, State	NY
Entity Address, Postal Zip Code	10001
City Area Code	212
Local Phone Number	492-1100
Entity Well Known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 0
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Central Index Key	0001558235
Class A
Cover
Entity Common Stock Shares Outstanding		119,148,270
Class C
Cover
Entity Common Stock Shares Outstanding		30,721,779