SENIOR NOTES PAYABLE AND OTHER DEBT - Credit Facilities, Commercial Paper, Unsecured Term Loans and Letters of Credit (Details)	9 Months Ended
	Sep. 30, 2025 USD ($) period	Dec. 31, 2024 USD ($)
Debt instruments
Commercial paper program capacity	$ 2,000,000,000.0
Commercial paper notes	0	$ 0
Mortgage loans and other	$ 12,664,182,000	13,618,802,000
Unsecured debt | Ventas Realty
Debt instruments
Variable interest rate	0.85%
Accordion feature of debt	$ 500,000,000
Unsecured debt	200,000,000
Unsecured debt | Revolving Credit Facility
Debt instruments
Maximum borrowing capacity	$ 3,500,000,000
Variable interest rate	0.775%
Additional periods | period	2
Additional period term	6 months
Fair value of amount outstanding	$ 0	6,397,000
Accordion feature of debt	4,500,000,000
Unsecured debt | Revolving Credit Facility | BAML
Debt instruments
Letters of credit outstanding	800,000
Unsecured debt | Letter of Credit
Debt instruments
Maximum borrowing capacity	100,000,000
Unsecured debt | Letter of Credit | Credit Agreement
Debt instruments
Letters of credit outstanding	18,300,000
Unsecured term loan due June 2027
Debt instruments
Unsecured debt	$ 500,000,000.0	$ 500,000,000
Interest rate	0.10%
Unsecured term loan due June 2027 | Ventas Realty
Debt instruments
Variable interest rate	0.85%
Accordion feature of debt	$ 1,250,000,000