CONDENSED CONSOLIDATING INFORMATION (Unaudited) - Statement of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Condensed Consolidating Statement of Cash Flows
Net cash (used in) provided by operating activities	$ 308,019	$ 345,814
Cash flows from investing activities:
Net investment in real estate property	(11,450)	(283,837)
Investment in loans receivable and other	(4,381)	(701,358)
Proceeds from real estate disposals	175,370	85,000
Proceeds from loans receivable	143,094	3,363
Development project expenditures	(73,889)	(86,452)
Capital expenditures	(20,617)	(23,835)
Investment in unconsolidated entities	(39,101)	(26,940)
Insurance proceeds for property damage claims	1,527	1,393
Net cash provided by (used in) investing activities	170,553	(1,032,666)
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	273,843	22,822
Proceeds from debt	738,519	797,214
Repayment of debt	(1,217,118)	(20,496)
Purchase of noncontrolling interests	0	(15,809)
Net change in intercompany debt	0	0
Payment of deferred financing costs	(6,318)	(6,384)
Cash distribution from (to) affiliates	0	0
Cash distribution to common stockholders	(281,635)	(275,368)
Cash distribution to redeemable OP unitholders	(1,858)	(1,893)
Contributions from noncontrolling interests	0	2,102
Cash issued for redemption of OP and Class C Units	(655)	0
Distributions to noncontrolling interests	(3,339)	(2,410)
Other	(4,687)	3,297
Net cash (used in) provided by financing activities	(503,248)	503,075
Net decrease in cash, cash equivalents and restricted cash	(24,676)	(183,777)
Effect of foreign currency translation	5	(118)
Cash, cash equivalents and restricted cash at beginning of period	188,253	367,354
Cash, cash equivalents and restricted cash at end of period	163,582	183,459
Consolidated Elimination
Condensed Consolidating Statement of Cash Flows
Net cash (used in) provided by operating activities	0	0
Cash flows from investing activities:
Net investment in real estate property	0	0
Investment in loans receivable and other	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 provided by (used in) investing activities	0	0
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	0	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 from (to) affiliates	0	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 and Class C Units	0
Distributions to noncontrolling interests	0	0
Other	0	0
Net cash (used in) provided by 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 (used in) provided by operating activities	(19,658)	4,275
Cash flows from investing activities:
Net investment in real estate property	(11,450)	(283,837)
Investment in loans receivable and other	(2,740)	(2,313)
Proceeds from real estate disposals	175,370	85,000
Proceeds from loans receivable	1,441	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 provided by (used in) investing activities	162,621	(201,150)
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	0	0
Proceeds from debt	0	0
Repayment of debt	0	0
Purchase of noncontrolling interests		(15,809)
Net change in intercompany debt	51,808	577,099
Payment of deferred financing costs	0	0
Cash distribution from (to) affiliates	50,937	(298,190)
Cash distribution to common stockholders	(281,635)	(275,368)
Cash distribution to redeemable OP unitholders	0	0
Contributions from noncontrolling interests		0
Cash issued for redemption of OP and Class C Units	0
Distributions to noncontrolling interests	0	0
Other	(4,687)	3,297
Net cash (used in) provided by financing activities	(183,577)	(8,971)
Net decrease in cash, cash equivalents and restricted cash	(40,614)	(205,846)
Effect of foreign currency translation	12,381	5,146
Cash, cash equivalents and restricted cash at beginning of period	49,644	210,501
Cash, cash equivalents and restricted cash at end of period	21,411	9,801
Ventas Realty
Condensed Consolidating Statement of Cash Flows
Net cash (used in) provided by operating activities	(58,563)	(32,622)
Cash flows from investing activities:
Net investment in real estate property	0	0
Investment in loans receivable and other	0	0
Proceeds from real estate disposals	0	0
Proceeds from loans receivable	0	0
Development project expenditures	0	0
Capital expenditures	0	(9)
Investment in unconsolidated entities	0	0
Insurance proceeds for property damage claims	0	0
Net cash provided by (used in) investing activities	0	(9)
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	266,764	18,000
Proceeds from debt	655,044	793,904
Repayment of debt	(1,211,811)	(19)
Purchase of noncontrolling interests		0
Net change in intercompany debt	354,019	(800,193)
Payment of deferred financing costs	(5,621)	(6,384)
Cash distribution from (to) affiliates	168	27,367
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 and Class C Units	0
Distributions to noncontrolling interests	0	0
Other	0	0
Net cash (used in) provided by financing activities	58,563	32,675
Net decrease in cash, cash equivalents and restricted cash	0	44
Effect of foreign currency translation	0	0
Cash, cash equivalents and restricted cash at beginning of period	128	1,504
Cash, cash equivalents and restricted cash at end of period	128	1,548
Ventas Subsidiaries
Condensed Consolidating Statement of Cash Flows
Net cash (used in) provided by operating activities	386,240	374,161
Cash flows from investing activities:
Net investment in real estate property	0	0
Investment in loans receivable and other	(1,641)	(699,045)
Proceeds from real estate disposals	0	0
Proceeds from loans receivable	141,653	3,363
Development project expenditures	(73,889)	(86,452)
Capital expenditures	(20,617)	(23,826)
Investment in unconsolidated entities	(39,101)	(26,940)
Insurance proceeds for property damage claims	1,527	1,393
Net cash provided by (used in) investing activities	7,932	(831,507)
Cash flows from financing activities:
Net change in borrowings under revolving credit facilities	7,079	4,822
Proceeds from debt	83,475	3,310
Repayment of debt	(5,307)	(20,477)
Purchase of noncontrolling interests		0
Net change in intercompany debt	(405,827)	223,094
Payment of deferred financing costs	(697)	0
Cash distribution from (to) affiliates	(51,105)	270,823
Cash distribution to common stockholders	0	0
Cash distribution to redeemable OP unitholders	(1,858)	(1,893)
Contributions from noncontrolling interests		2,102
Cash issued for redemption of OP and Class C Units	(655)
Distributions to noncontrolling interests	(3,339)	(2,410)
Other	0	0
Net cash (used in) provided by financing activities	(378,234)	479,371
Net decrease in cash, cash equivalents and restricted cash	15,938	22,025
Effect of foreign currency translation	(12,376)	(5,264)
Cash, cash equivalents and restricted cash at beginning of period	138,481	155,349
Cash, cash equivalents and restricted cash at end of period	$ 142,043	$ 172,110