Condensed Consolidating Information (Cash Flow Statement) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	$ 1,367,457	$ 1,391,767	$ 1,254,845
Cash flows from investing activities:
Net investment in real estate property	(1,429,112)	(2,650,788)	(1,468,286)
Investment in loans receivable and other	(158,635)	(171,144)	(498,992)
Proceeds from real estate disposals	300,561	492,408	118,246
Proceeds from loans receivable	320,082	109,176	73,557
Purchase of marketable securities	0	0	(96,689)
Proceeds from sale or maturity of marketable securities	0	76,800	21,689
Funds held in escrow for future development expenditures	0	4,003	4,590
Development project expenditures	(143,647)	(119,674)	(106,988)
Capital expenditures	(117,456)	(107,487)	(87,454)
Investment in unconsolidated operating entity	0	(26,282)	0
Contributions to unconsolidated entities	0	(30,704)	(5,598)
Other	(6,436)	0	(9,115)
Net cash used in investing activities	(1,234,643)	(2,423,692)	(2,055,040)
Cash flows from financing activities:
Net change in borrowings under credit facilities	(35,637)	(723,457)	540,203
Net cash impact of CCP Spin-Off	0	(128,749)	0
Proceeds from debt	893,218	2,512,747	2,007,707
Issuance of debt related to CCP spin-off	0	1,400,000	0
Repayment of debt	(1,022,113)	(1,435,596)	(1,151,395)
Net change in intercompany debt	0	0	0
Purchase of noncontrolling interest	(2,846)	(3,819)
Payment of deferred financing costs	(6,555)	(24,665)	(14,220)
Issuance of common stock, net	1,286,680	491,023	242,107
Cash distribution from (to) affiliates	0	0	0
Cash distribution to common stockholders	(1,024,968)	(1,003,413)	(875,614)
Cash distribution to redeemable OP unitholders	(8,640)	(15,095)	(5,762)
Purchases of redeemable OP units	0	(33,188)	(503)
Contributions from noncontrolling interest	7,326	0	491
Distributions to noncontrolling interest	(6,879)	(12,649)	(9,559)
Other	22,136	6,983	24,602
Net cash provided by (used in) financing activities	101,722	1,030,122	758,057
Net increase (decrease) in cash and cash equivalents	234,536	(1,803)	(42,138)
Effect of foreign currency translation on cash and cash equivalents	(852)	(522)	2,670
Cash and cash equivalents at beginning of period	53,023	55,348	94,816
Cash and cash equivalents at end of period	286,707	53,023	55,348
Consolidated Elimination
Cash flows from investing activities:
Net investment in real estate property	0	0	0
Investment in loans receivable and other		0	0
Proceeds from real estate disposals	0	0	0
Proceeds from loans receivable	0	0	0
Purchase of marketable securities			0
Proceeds from sale or maturity of marketable securities		0	0
Funds held in escrow for future development expenditures		0	0
Development project expenditures	0	0	0
Capital expenditures	0	0	0
Investment in unconsolidated operating entity		0
Contributions to unconsolidated entities		0	0
Other	0		0
Net cash used in investing activities	0	0	0
Cash flows from financing activities:
Contributions from noncontrolling interest	0
Ventas, Inc.
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	65,121	(123,041)	(95,331)
Cash flows from investing activities:
Net investment in real estate property	(1,448,230)	(2,650,788)	(1,468,286)
Investment in loans receivable and other	0	0	0
Proceeds from real estate disposals	257,441	492,408	118,246
Proceeds from loans receivable	0	0	0
Purchase of marketable securities			0
Proceeds from sale or maturity of marketable securities		76,800	0
Funds held in escrow for future development expenditures		0	0
Development project expenditures	0	0	0
Capital expenditures	0	0	0
Investment in unconsolidated operating entity		(26,282)
Contributions to unconsolidated entities		0	(5,527)
Other	0		(2,689)
Net cash used in investing activities	(1,190,789)	(2,107,862)	(1,358,256)
Cash flows from financing activities:
Net cash impact of CCP Spin-Off		1,273,000
Net change in intercompany debt	990,056	1,782,954	1,300,790
Issuance of common stock, net	1,286,680	491,023	242,107
Cash distribution from (to) affiliates	106,723	(315,466)	776,497
Cash distribution to common stockholders	(1,024,968)	(1,003,413)	(875,614)
Cash distribution to redeemable OP unitholders			(5,762)
Purchases of redeemable OP units			(503)
Contributions from noncontrolling interest	0
Other	22,136	6,983	24,597
Net cash provided by (used in) financing activities	1,380,627	2,235,081	1,462,112
Net increase (decrease) in cash and cash equivalents	254,959	4,178	8,525
Effect of foreign currency translation on cash and cash equivalents	(56,389)	(17,302)	(11,837)
Cash and cash equivalents at beginning of period	11,733	24,857	28,169
Cash and cash equivalents at end of period	210,303	11,733	24,857
Ventas Realty
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	(93,432)	16,528	80,263
Cash flows from investing activities:
Net investment in real estate property	0	0	0
Investment in loans receivable and other	0	0	0
Proceeds from real estate disposals	0	0	0
Proceeds from loans receivable	0	0	0
Purchase of marketable securities			0
Proceeds from sale or maturity of marketable securities		0	0
Funds held in escrow for future development expenditures		0	0
Development project expenditures	0	0	0
Capital expenditures	(314)	(15,733)	(7,749)
Investment in unconsolidated operating entity		0
Contributions to unconsolidated entities		0	0
Other	0		0
Net cash used in investing activities	(314)	(15,733)	(7,749)
Cash flows from financing activities:
Net change in borrowings under credit facilities	(171,000)	(584,000)	386,000
Proceeds from debt	846,521	2,292,568	696,661
Repayment of debt	(651,820)	(705,000)
Net change in intercompany debt	82,266	(1,008,773)	(895,961)
Payment of deferred financing costs	(5,787)	(22,297)	(6,608)
Cash distribution from (to) affiliates	(6,434)	26,707	(252,611)
Contributions from noncontrolling interest	0
Other			5
Net cash provided by (used in) financing activities	93,746	(795)	(72,514)
Ventas Subsidiaries
Condensed Consolidating Statement of Cash Flows
Net cash provided by (used in) operating activities	1,395,768	1,498,280	1,269,913
Cash flows from investing activities:
Net investment in real estate property	19,118	0	0
Investment in loans receivable and other	(158,635)	(171,144)	(498,992)
Proceeds from real estate disposals	43,120	0	0
Proceeds from loans receivable	320,082	109,176	73,557
Purchase of marketable securities			(96,689)
Proceeds from sale or maturity of marketable securities		0	21,689
Funds held in escrow for future development expenditures		4,003	4,590
Development project expenditures	(143,647)	(119,674)	(106,988)
Capital expenditures	(117,142)	(91,754)	(79,705)
Investment in unconsolidated operating entity		0
Contributions to unconsolidated entities		(30,704)	(71)
Other	(6,436)		(6,426)
Net cash used in investing activities	(43,540)	(300,097)	(689,035)
Cash flows from financing activities:
Net change in borrowings under credit facilities	135,363	(139,457)	154,203
Net cash impact of CCP Spin-Off		(1,401,749)
Proceeds from debt	46,697	220,179	1,311,046
Issuance of debt related to CCP spin-off		1,400,000
Repayment of debt	(370,293)	(730,596)	(1,151,395)
Net change in intercompany debt	(1,072,322)	(774,181)	(404,829)
Purchase of noncontrolling interest	(2,846)	(3,819)
Payment of deferred financing costs	(768)	(2,368)	(7,612)
Cash distribution from (to) affiliates	(100,289)	288,759	(523,886)
Cash distribution to redeemable OP unitholders	(8,640)	(15,095)
Purchases of redeemable OP units		(33,188)
Contributions from noncontrolling interest	7,326		491
Distributions to noncontrolling interest	(6,879)	(12,649)	(9,559)
Net cash provided by (used in) financing activities	(1,372,651)	(1,204,164)	(631,541)
Net increase (decrease) in cash and cash equivalents	(20,423)	(5,981)	(50,663)
Effect of foreign currency translation on cash and cash equivalents	55,537	16,780	14,507
Cash and cash equivalents at beginning of period	41,290	30,491	66,647
Cash and cash equivalents at end of period	$ 76,404	$ 41,290	$ 30,491