CONDENSED CONSOLIDATING INFORMATION (Unaudited) - Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	$ 336,120	$ 308,019
Cash flows from investing activities:
Net investment in real estate property	(13,097)	(11,450)
Investment in loans receivable	(4,257)	(4,381)
Proceeds from real estate disposals	17,551	175,370
Proceeds from loans receivable	1,275	143,094
Development project expenditures	(49,652)	(73,889)
Capital expenditures	(21,955)	(20,617)
Investment in unconsolidated entities	(687)	(39,101)
Insurance proceeds for property damage claims	2,998	1,527
Net cash (used in) provided by investing activities	(67,824)	170,553
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	(700,775)	273,843
Net change in borrowings under commercial paper program	194,498	0
Proceeds from debt	706,591	738,519
Repayment of debt	(262,570)	(1,217,118)
Net change in intercompany debt	0	0
Payment of deferred financing costs	(6,837)	(6,318)
Issuance of common stock, net	98,378	0
Cash distribution to common stockholders	(282,874)	(281,635)
Cash distribution to redeemable OP unitholders	(2,216)	(1,858)
Contributions from noncontrolling interests	1,223	0
Cash issued for redemption of OP Units	0	(655)
Distributions to noncontrolling interests	(2,623)	(3,339)
Other	(2,558)	(4,687)
Net cash used in financing activities	(259,763)	(503,248)
Net decrease in cash, cash equivalents and restricted cash	8,533	(24,676)
Effect of foreign currency translation	234	5
Cash, cash equivalents and restricted cash at beginning of period	131,464	188,253
Cash, cash equivalents and restricted cash at end of period	140,231	163,582
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
Capital expenditures	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
Net change in intercompany debt	0	0
Payment of deferred financing costs	0	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
Cash issued for redemption of OP Units		0
Distributions to noncontrolling interests	0	0
Other	0	0
Net cash used in financing activities	0	0
Net 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	10,545	(19,936)
Cash flows from investing activities:
Net investment in real estate property	(13,097)	(11,450)
Investment in loans receivable	(2,335)	(2,740)
Proceeds from real estate disposals	17,551	175,370
Proceeds from loans receivable	11	1,441
Development project expenditures	0	0
Capital expenditures	0	0
Investment in unconsolidated entities	0	0
Insurance proceeds for property damage claims		0
Net cash (used in) provided by investing activities	2,130	162,621
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	(168)
Net change in intercompany debt	172,998	103,372
Payment of deferred financing costs	0	0
Issuance of common stock, net	98,378
Cash distribution to common stockholders	(282,874)	(281,635)
Cash distribution to redeemable OP unitholders	0	0
Contributions from noncontrolling interests	0
Cash issued for redemption of OP Units		0
Distributions to noncontrolling interests	0	0
Other	(2,552)	(4,687)
Net cash used in financing activities	(14,050)	(183,118)
Net decrease in cash, cash equivalents and restricted cash	(1,375)	(40,433)
Effect of foreign currency translation	6,631	12,381
Cash, cash equivalents and restricted cash at beginning of period	10,681	46,945
Cash, cash equivalents and restricted cash at end of period	15,937	18,893
Ventas Realty
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	(68,079)	(58,562)
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
Capital expenditures	0	0
Investment in unconsolidated entities	0	0
Insurance proceeds for property damage claims		0
Net cash (used in) provided by investing activities	0	0
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	(700,858)	266,764
Net change in borrowings under commercial paper program	194,498
Proceeds from debt	698,822	655,044
Repayment of debt	(258,750)	(1,211,643)
Net change in intercompany debt	141,204	354,018
Payment of deferred financing costs	(6,837)	(5,621)
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
Cash issued for redemption of OP Units		0
Distributions to noncontrolling interests	0	0
Other	0	0
Net cash used in financing activities	68,079	58,562
Net 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	393,654	386,517
Cash flows from investing activities:
Net investment in real estate property	0	0
Investment in loans receivable	(1,922)	(1,641)
Proceeds from real estate disposals	0	0
Proceeds from loans receivable	1,264	141,653
Development project expenditures	(49,652)	(73,889)
Capital expenditures	(21,955)	(20,617)
Investment in unconsolidated entities	(687)	(39,101)
Insurance proceeds for property damage claims	2,998	1,527
Net cash (used in) provided by investing activities	(69,954)	7,932
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	83	7,079
Net change in borrowings under commercial paper program	0
Proceeds from debt	7,769	83,475
Repayment of debt	(3,820)	(5,307)
Net change in intercompany debt	(314,202)	(457,390)
Payment of deferred financing costs	0	(697)
Issuance of common stock, net	0
Cash distribution to common stockholders	0	0
Cash distribution to redeemable OP unitholders	(2,216)	(1,858)
Contributions from noncontrolling interests	1,223
Cash issued for redemption of OP Units		(655)
Distributions to noncontrolling interests	(2,623)	(3,339)
Other	(6)	0
Net cash used in financing activities	(313,792)	(378,692)
Net decrease in cash, cash equivalents and restricted cash	9,908	15,757
Effect of foreign currency translation	(6,397)	(12,376)
Cash, cash equivalents and restricted cash at beginning of period	120,655	141,180
Cash, cash equivalents and restricted cash at end of period	$ 124,166	$ 144,561