SENIOR NOTES PAYABLE AND OTHER DEBT - Credit Facilities, Commercial Paper, Unsecured Term Loans and Letters of Credit (Details)	1 Months Ended	3 Months Ended
	Apr. 30, 2025 USD ($)	Mar. 31, 2025 USD ($) period	Dec. 31, 2024 USD ($)
Debt instruments
Letters of credit outstanding		$ 17,400,000
Commercial paper program capacity		1,000,000,000.0
Commercial paper notes		243,000,000	$ 0
Unsecured debt | Ventas Realty
Debt instruments
Accordion feature of debt		500,000,000
Unsecured debt		$ 200,000,000
Unsecured debt | Ventas Realty | Adjusted SOFR
Debt instruments
Variable interest rate		0.85%
Unsecured debt | Revolving Credit Facility
Debt instruments
Maximum borrowing capacity		$ 2,750,000,000
Variable interest rate		0.775%
Additional periods | period		2
Additional period term		6 months
Remaining borrowing capacity		$ 2,750,000,000
Fair value of amount outstanding		0	6,397,000
Letters of credit outstanding		$ 800,000
Unsecured debt | Revolving Credit Facility | SOFR
Debt instruments
Variable interest rate		0.10%
Unsecured debt | Revolving Credit Facility | Subsequent Event
Debt instruments
Maximum borrowing capacity	$ 3,500,000,000
Variable interest rate	0.775%
Accordion feature of debt	$ 4,500,000,000
Unsecured debt | Letter of Credit
Debt instruments
Maximum borrowing capacity		$ 100,000,000
Unsecured term loan due June 2027
Debt instruments
Unsecured debt		500,000,000.0	$ 500,000,000
Unsecured term loan due June 2027 | Ventas Realty
Debt instruments
Accordion feature of debt		$ 1,250,000,000
Unsecured term loan due June 2027 | Ventas Realty | Adjusted SOFR
Debt instruments
Variable interest rate		0.85%