Cover Page - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Feb. 04, 2022	Jun. 30, 2021
Entity Information [Line Items]
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	1-8923
Entity Registrant Name	WELLTOWER INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	34-1096634
Entity Address, Address Line One	4500 Dorr Street,
Entity Address, City or Town	Toledo,
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	43615
City Area Code	419
Local Phone Number	247-2800
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
Entity Shell Company	false
ICFR Auditor Attestation Flag	true
Entity Public Float			$ 35,091,527
Entity Common Stock, Shares Outstanding		447,279,642
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement for the annual stockholders’ meeting to be held May 9, 2022, are incorporated by reference into Part III.
Entity Central Index Key	0000766704
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Common Stock, $1.00 par value
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $1.00 par value
Trading Symbol	WELL
Security Exchange Name	NYSE
4.800% Notes due 2028
Entity Information [Line Items]
Title of 12(b) Security	4.800% Notes due 2028
Trading Symbol	WELL28
Security Exchange Name	NYSE
4.500% Notes due 2034
Entity Information [Line Items]
Title of 12(b) Security	4.500% Notes due 2034
Trading Symbol	WELL34
Security Exchange Name	NYSE