CONDENSED CONSOLIDATING INFORMATION (Unaudited) - Statement of Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	$ 1,083,548	$ 1,017,622
Cash flows from investing activities:
Net investment in real estate property	(939,805)	(35,800)
Investment in loans receivable	(1,257,577)	(212,089)
Proceeds from real estate disposals	77,555	331,243
Proceeds from loans receivable	1,008,683	866,313
Development project expenditures	(229,845)	(230,348)
Payments for Capital Improvements	99,787	73,025
Distributions from unconsolidated entities	151	57,430
Investment in unconsolidated entities	(1,711)	(45,106)
Insurance proceeds for property damage claims	20,457	6,327
Net cash (used in) provided by investing activities	(1,421,879)	664,945
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	278,677	41,292
Net change in borrowings under commercial paper program	304,508	0
Proceeds from debt	2,206,577	2,412,420
Repayment of debt	(2,456,135)	(3,294,104)
Purchase of noncontrolling interests		(2,429)
Net change in intercompany debt	0	0
Payment of deferred financing costs	(17,867)	(16,583)
Cash distribution (to) from affiliates		0
Issuance of common stock, net	942,250	0
Cash distribution to common stockholders	(861,789)	(845,248)
Cash distribution to redeemable OP unitholders	(6,882)	(5,594)
Contributions from noncontrolling interests	4,959	500
Cash issued for redemption of OP Units	(361)	(1,370)
Distributions to noncontrolling interests	(6,403)	(9,968)
Proceeds from stock option exercises	34,134	4,238
Other	(6,601)	(4,974)
Net cash used in financing activities	415,067	(1,721,820)
Net increase (decrease) in cash, cash equivalents and restricted cash	76,736	(39,253)
Effect of foreign currency translation	396	(453)
Cash, cash equivalents and restricted cash at beginning of period	131,464	188,253
Cash, cash equivalents and restricted cash at end of period	208,596	148,547
Consolidated Elimination
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	0	0
Cash flows from investing activities:
Net investment in real estate property	0	0
Investment in loans receivable	0	0
Proceeds from real estate disposals	0	0
Proceeds from loans receivable	0	0
Development project expenditures	0	0
Payments for Capital Improvements	0	0
Distributions from unconsolidated entities	0	0
Investment in unconsolidated entities	0	0
Insurance proceeds for property damage claims	0	0
Net cash (used in) provided by investing activities	0	0
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	0	0
Net change in borrowings under commercial paper program	0
Proceeds from debt	0	0
Repayment of debt	0	0
Purchase of noncontrolling interests		0
Net change in intercompany debt	0	0
Payment of deferred financing costs	0	0
Cash distribution (to) from affiliates		0
Issuance of common stock, net	0
Cash distribution to common stockholders	0	0
Cash distribution to redeemable OP unitholders	0	0
Contributions from noncontrolling interests	0	0
Cash issued for redemption of OP Units	0	0
Distributions to noncontrolling interests	0	0
Proceeds from stock option exercises	0	0
Other	0	0
Net cash used in financing activities	0	0
Net increase (decrease) in cash, cash equivalents and restricted cash	0	0
Effect of foreign currency translation	0	0
Cash, cash equivalents and restricted cash at beginning of period	0	0
Cash, cash equivalents and restricted cash at end of period	0	0
Ventas, Inc.
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	19,196	30,077
Cash flows from investing activities:
Net investment in real estate property	(217,486)	(35,800)
Investment in loans receivable	(21,579)	(3,036)
Proceeds from real estate disposals	77,245	331,243
Proceeds from loans receivable	44	1,473
Development project expenditures	0	0
Payments for Capital Improvements	0	0
Distributions from unconsolidated entities	0	0
Investment in unconsolidated entities	0	0
Insurance proceeds for property damage claims	0	0
Net cash (used in) provided by investing activities	(161,776)	293,880
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	0	0
Net change in borrowings under commercial paper program	0
Proceeds from debt	0	0
Repayment of debt	0	0
Purchase of noncontrolling interests		(2,429)
Net change in intercompany debt	54,413	976,533
Payment of deferred financing costs	0	0
Cash distribution (to) from affiliates		473,343
Issuance of common stock, net	942,250
Cash distribution to common stockholders	(861,789)	(845,248)
Cash distribution to redeemable OP unitholders	0	0
Contributions from noncontrolling interests	0	0
Cash issued for redemption of OP Units	0	0
Distributions to noncontrolling interests	0	0
Proceeds from stock option exercises	34,134	4,238
Other	(6,592)	(4,974)
Net cash used in financing activities	162,416	(345,223)
Net increase (decrease) in cash, cash equivalents and restricted cash	19,836	(21,266)
Effect of foreign currency translation	(11,557)	(12,190)
Cash, cash equivalents and restricted cash at beginning of period	10,681	46,945
Cash, cash equivalents and restricted cash at end of period	18,960	13,489
Ventas Realty
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	(158,086)	(163,311)
Cash flows from investing activities:
Net investment in real estate property	0	0
Investment in loans receivable	0	0
Proceeds from real estate disposals	0	0
Proceeds from loans receivable	0	0
Development project expenditures	(169)	0
Payments for Capital Improvements	0	0
Distributions from unconsolidated entities	0	0
Investment in unconsolidated entities	0	0
Insurance proceeds for property damage claims	0	0
Net cash (used in) provided by investing activities	(169)	0
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	(407,381)	49,438
Net change in borrowings under commercial paper program	304,508
Proceeds from debt	1,793,154	2,309,141
Repayment of debt	(2,109,880)	(2,949,456)
Purchase of noncontrolling interests		0
Net change in intercompany debt	594,202	769,781
Payment of deferred financing costs	(16,348)	(15,593)
Cash distribution (to) from affiliates		0
Issuance of common stock, net	0
Cash distribution to common stockholders	0	0
Cash distribution to redeemable OP unitholders	0	0
Contributions from noncontrolling interests	0	0
Cash issued for redemption of OP Units	0	0
Distributions to noncontrolling interests	0	0
Proceeds from stock option exercises	0	0
Other	0	0
Net cash used in financing activities	158,255	163,311
Net increase (decrease) in cash, cash equivalents and restricted cash	0	0
Effect of foreign currency translation	0	0
Cash, cash equivalents and restricted cash at beginning of period	128	128
Cash, cash equivalents and restricted cash at end of period	128	128
Ventas Subsidiaries
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	1,222,438	1,150,856
Cash flows from investing activities:
Net investment in real estate property	(722,319)	0
Investment in loans receivable	(1,235,998)	(209,053)
Proceeds from real estate disposals	310	0
Proceeds from loans receivable	1,008,639	864,840
Development project expenditures	(229,676)	(230,348)
Payments for Capital Improvements	99,787	73,025
Distributions from unconsolidated entities	151	57,430
Investment in unconsolidated entities	(1,711)	(45,106)
Insurance proceeds for property damage claims	20,457	6,327
Net cash (used in) provided by investing activities	(1,259,934)	371,065
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	686,058	(8,146)
Net change in borrowings under commercial paper program	0
Proceeds from debt	413,423	103,279
Repayment of debt	(346,255)	(344,648)
Purchase of noncontrolling interests		0
Net change in intercompany debt	(648,615)	(1,746,314)
Payment of deferred financing costs	(1,519)	(990)
Cash distribution (to) from affiliates		(473,343)
Issuance of common stock, net	0
Cash distribution to common stockholders	0	0
Cash distribution to redeemable OP unitholders	(6,882)	(5,594)
Contributions from noncontrolling interests	4,959	500
Cash issued for redemption of OP Units	(361)	(1,370)
Distributions to noncontrolling interests	(6,403)	(9,968)
Proceeds from stock option exercises	0	0
Other	(9)	0
Net cash used in financing activities	94,396	(1,539,908)
Net increase (decrease) in cash, cash equivalents and restricted cash	56,900	(17,987)
Effect of foreign currency translation	11,953	11,737
Cash, cash equivalents and restricted cash at beginning of period	120,655	141,180
Cash, cash equivalents and restricted cash at end of period	$ 189,508	$ 134,930