CONDENSED CONSOLIDATING INFORMATION - Statement of Cash Flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Mar. 31, 2015
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	$ 656,475	$ 717,724
Cash flows from investing activities:
Net investment in real estate property	(34,453)	(1,253,910)
Proceeds from loans receivable	7,644	93,275
Investment in loans receivable and other	(152,450)	(55,659)
Funds held in escrow for future development expenditures	0	4,003
Proceeds from real estate disposals	63,561	273,191
Proceeds from sale or maturity of marketable securities	0	57,225
Capital expenditures	(46,925)	(43,429)
Development project expenditures	(69,679)	(62,630)
Other	(4,265)	(8,813)
Net cash used in investing activities	(236,567)	(996,747)
Cash flows from financing activities:
Net change in borrowings under credit facility	24,304	(321,334)
Proceeds from debt	416,217	1,107,971
Repayment of debt	(740,337)	(278,442)
Purchase of noncontrolling interest	(1,604)	(3,816)
Net change in intercompany debt	0	0
Payment of deferred financing costs	(3,844)	(14,608)
Issuance of common stock, net	377,739	352,167
Cash distribution (to) from affiliates	0	0
Cash distribution to common stockholders	(493,471)	(516,404)
Cash distribution to redeemable OP unitholders	(4,437)	(4,697)
Contributions from noncontrolling interest	5,680	0
Purchases of redeemable OP units	0	(33,188)
Distributions to noncontrolling interest	(3,582)	(9,467)
Other	7,883	5,928
Net cash (used in) provided by financing activities	(415,452)	284,110
Net increase in cash and cash equivalents	4,456	5,087
Effect of foreign currency translation on cash and cash equivalents	(157)	97
Cash and cash equivalents at beginning of period	53,023	55,348
Cash and cash equivalents at end of period	57,322	60,532
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
Proceeds from loans receivable	0	0
Investment in loans receivable and other	0	0
Funds held in escrow for future development expenditures		0
Proceeds from real estate disposals	0	0
Proceeds from sale or maturity of marketable securities		0
Capital expenditures	0	0
Development project expenditures	0	0
Other	0	0
Net cash used in investing activities	0	0
Cash flows from financing activities:
Net change in borrowings under credit facility	0	0
Proceeds from debt	0	0
Repayment of debt	0	0
Purchase of noncontrolling interest	0	0
Net change in intercompany debt	0	0
Payment of deferred financing costs	0	0
Issuance of common stock, net	0	0
Cash distribution (to) from affiliates	0	0
Cash distribution to common stockholders	0	0
Cash distribution to redeemable OP unitholders	0	0
Contributions from noncontrolling interest	0
Purchases of redeemable OP units		0
Distributions to noncontrolling interest	0	0
Other	0	0
Net cash (used in) provided by financing activities	0	0
Net increase in cash and cash equivalents	0	0
Effect of foreign currency translation on cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Ventas, Inc.
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	36,414	(42,987)
Cash flows from investing activities:
Net investment in real estate property	(34,453)	(1,253,910)
Proceeds from loans receivable	0	0
Investment in loans receivable and other	0	0
Funds held in escrow for future development expenditures		0
Proceeds from real estate disposals	20,441	273,191
Proceeds from sale or maturity of marketable securities		57,225
Capital expenditures	0	0
Development project expenditures	0	0
Other	0	0
Net cash used in investing activities	(14,012)	(923,494)
Cash flows from financing activities:
Net change in borrowings under credit facility	0	45,000
Proceeds from debt	0	0
Repayment of debt	0	0
Purchase of noncontrolling interest	0	0
Net change in intercompany debt	128,165	1,295,130
Payment of deferred financing costs	0	0
Issuance of common stock, net	377,739	352,167
Cash distribution (to) from affiliates	(8,101)	(233,483)
Cash distribution to common stockholders	(493,471)	(516,404)
Cash distribution to redeemable OP unitholders	0
Contributions from noncontrolling interest	0
Purchases of redeemable OP units		0
Distributions to noncontrolling interest	0	0
Other	7,883	5,928
Net cash (used in) provided by financing activities	12,215	948,338
Net increase in cash and cash equivalents	34,617	(18,143)
Effect of foreign currency translation on cash and cash equivalents	(33,353)	5,004
Cash and cash equivalents at beginning of period	11,733	24,857
Cash and cash equivalents at end of period	12,997	11,718
Ventas Realty
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	(45,318)	65,028
Cash flows from investing activities:
Net investment in real estate property	0	0
Proceeds from loans receivable	0	0
Investment in loans receivable and other	0	0
Funds held in escrow for future development expenditures		0
Proceeds from real estate disposals	0	0
Proceeds from sale or maturity of marketable securities		0
Capital expenditures	(18)	(10,153)
Development project expenditures	0	0
Other	0	0
Net cash used in investing activities	(18)	(10,153)
Cash flows from financing activities:
Net change in borrowings under credit facility	(114,000)	(228,000)
Proceeds from debt	400,000	896,478
Repayment of debt	(555,470)	0
Purchase of noncontrolling interest	0	0
Net change in intercompany debt	308,816	(711,399)
Payment of deferred financing costs	(3,422)	(12,755)
Issuance of common stock, net	0	0
Cash distribution (to) from affiliates	9,412	801
Cash distribution to common stockholders	0	0
Cash distribution to redeemable OP unitholders	0	0
Contributions from noncontrolling interest	0
Purchases of redeemable OP units		0
Distributions to noncontrolling interest	0	0
Other	0
Net cash (used in) provided by financing activities	45,336	(54,875)
Net increase in cash and cash equivalents	0	0
Effect of foreign currency translation on cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	$ 0	0
Ownership percentage	100.00%
Ventas Subsidiaries
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	$ 665,379	695,683
Cash flows from investing activities:
Net investment in real estate property	0	0
Proceeds from loans receivable	7,644	93,275
Investment in loans receivable and other	(152,450)	(55,659)
Funds held in escrow for future development expenditures		4,003
Proceeds from real estate disposals	43,120	0
Proceeds from sale or maturity of marketable securities		0
Capital expenditures	(46,907)	(33,276)
Development project expenditures	(69,679)	(62,630)
Other	(4,265)	(8,813)
Net cash used in investing activities	(222,537)	(63,100)
Cash flows from financing activities:
Net change in borrowings under credit facility	138,304	(138,334)
Proceeds from debt	16,217	211,493
Repayment of debt	(184,867)	(278,442)
Purchase of noncontrolling interest	(1,604)	(3,816)
Net change in intercompany debt	(436,981)	(583,731)
Payment of deferred financing costs	(422)	(1,853)
Issuance of common stock, net	0	0
Cash distribution (to) from affiliates	(1,311)	232,682
Cash distribution to common stockholders	0	0
Cash distribution to redeemable OP unitholders	(4,437)	(4,697)
Contributions from noncontrolling interest	5,680
Purchases of redeemable OP units		(33,188)
Distributions to noncontrolling interest	(3,582)	(9,467)
Other	0	0
Net cash (used in) provided by financing activities	(473,003)	(609,353)
Net increase in cash and cash equivalents	(30,161)	23,230
Effect of foreign currency translation on cash and cash equivalents	33,196	(4,907)
Cash and cash equivalents at beginning of period	41,290	30,491
Cash and cash equivalents at end of period	$ 44,325	$ 48,814
Ventas Capital Corporation
Cash flows from financing activities:
Ownership percentage	100.00%	100.00%	100.00%	100.00%