Cover Page - shares	6 Months Ended
	Jun. 30, 2021	Jul. 23, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
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 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
Entity Common Stock Shares Outstanding		422,562,838
Entity Central Index Key	0000766704
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Common stock, $1.00 par value per share
Document Information [Line Items]
Title of 12(b) Security	Common stock, $1.00 par value per share
Trading Symbol	WELL
Security Exchange Name	NYSE
4.800% Notes due 2028
Document 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
Document Information [Line Items]
Title of 12(b) Security	4.500% Notes due 2034
Trading Symbol	WELL34
Security Exchange Name	NYSE