Condensed Consolidating Information (Income Statement) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Rental income									$ 1,433,995	$ 1,327,383	$ 1,180,731
Resident fees and services									1,552,951	1,406,005	1,227,124
Medical office building and other services revenue									29,364	17,809	20,741
Income from loans and investments									55,169	58,208	39,913
Equity earnings in affiliates									0	0	0
Interest and other income									4,267	2,047	1,106
Total revenues	803,987	779,035	751,254	741,470	733,185	711,249	684,109	682,909	3,075,746	2,811,452	2,469,615
Expenses:
Interest									376,842	334,909	288,717
Depreciation and amortization									826,911	722,075	714,967
Property-level operating expenses									1,195,098	1,109,632	966,422
Medical office building services costs									17,092	8,315	9,883
General, administrative and professional fees									121,746	115,106	98,510
Loss on extinguishment of debt, net									5,564	1,201	37,640
Merger-related expenses and deal costs									45,051	21,634	63,183
Other									38,925	18,732	6,940
Total expenses									2,627,229	2,331,604	2,186,262
Income before income (loss) from unconsolidated entities, income taxes, discontinued operations and noncontrolling interest									448,517	479,848	283,353
(Loss) income from unconsolidated entities									(139)	(508)	18,154
Income tax benefit									8,732	11,828	6,282
Income from continuing operations									457,110	491,168	307,789
Discontinued operations	(411)	(259)	(255)	3,031	(115)	(9,174)	(18,559)	(8,431)	2,106	(36,279)	53,986
Gain on real estate dispositions									17,970	0	0
Net income									477,186	454,889	361,775
Net (loss) income attributable to noncontrolling interest, net of tax									1,419	1,380	(1,025)
Net income attributable to common stockholders	107,190	109,132	138,398	121,047	108,440	118,296	114,580	112,193	475,767	453,509	362,800
Ventas, Inc.
Revenues:
Rental income									2,789	2,486	2,538
Income from loans and investments									3,052	1,262	2,944
Equity earnings in affiliates									480,273	449,678	322,662
Interest and other income									3,314	2,963	476
Total revenues									489,428	456,389	328,620
Expenses:
Interest									(18,209)	(2,167)	(3,858)
Depreciation and amortization									5,860	4,991	2,777
Property-level operating expenses									1
General, administrative and professional fees									3,910	2,695	3,682
Loss on extinguishment of debt, net									(3)	3
Merger-related expenses and deal costs									27,841	11,917	53,200
Other									22,169	884	79
Total expenses									41,569	18,323	55,880
Income before income (loss) from unconsolidated entities, income taxes, discontinued operations and noncontrolling interest									447,859	438,066	272,740
Income tax benefit									8,732	11,828	6,282
Income from continuing operations									456,591	449,894	279,022
Discontinued operations									1,206	3,615	83,778
Gain on real estate dispositions									17,970
Net income									475,767	453,509	362,800
Net income attributable to common stockholders									475,767	453,509	362,800
Ventas Realty
Revenues:
Rental income									282,174	278,288	273,524
Medical office building and other services revenue										(11)
Income from loans and investments										908	1,871
Interest and other income									26	26	25
Total revenues									282,200	279,211	275,420
Expenses:
Interest									197,704	147,250	92,692
Depreciation and amortization									32,736	30,018	35,511
Property-level operating expenses									481	514	535
General, administrative and professional fees									20,569	21,160	30,317
Loss on extinguishment of debt, net									3	1,510	39,737
Merger-related expenses and deal costs									2,110
Other									488	44
Total expenses									254,091	200,496	198,792
Income before income (loss) from unconsolidated entities, income taxes, discontinued operations and noncontrolling interest									28,109	78,715	76,628
(Loss) income from unconsolidated entities									1,250	673	18,266
Income from continuing operations									29,359	79,388	94,894
Discontinued operations									(1,198)	605	4,897
Net income									28,161	79,993	99,791
Net income attributable to common stockholders									28,161	79,993	99,791
Ventas Subsidiaries
Revenues:
Rental income									1,149,032	1,046,609	904,669
Resident fees and services									1,552,951	1,406,005	1,227,124
Medical office building and other services revenue									29,364	17,820	20,741
Income from loans and investments									52,117	56,038	35,098
Equity earnings in affiliates									281	800	997
Interest and other income									927	(942)	605
Total revenues									2,784,672	2,526,330	2,189,234
Expenses:
Interest									197,347	189,826	199,883
Depreciation and amortization									788,315	687,066	676,679
Property-level operating expenses									1,194,616	1,109,118	965,887
Medical office building services costs									17,092	8,315	9,883
General, administrative and professional fees									97,267	91,251	64,511
Loss on extinguishment of debt, net									5,564	(312)	(2,097)
Merger-related expenses and deal costs									15,100	9,717	9,983
Other									16,268	17,804	6,861
Total expenses									2,331,569	2,112,785	1,931,590
Income before income (loss) from unconsolidated entities, income taxes, discontinued operations and noncontrolling interest									453,103	413,545	257,644
(Loss) income from unconsolidated entities									(1,389)	(1,181)	(112)
Income from continuing operations									451,714	412,364	257,532
Discontinued operations									2,098	(40,499)	(34,689)
Net income									453,812	371,865	222,843
Net (loss) income attributable to noncontrolling interest, net of tax									1,419	1,380	(1,025)
Net income attributable to common stockholders									452,393	370,485	223,868
Consolidated Elimination
Revenues:
Equity earnings in affiliates									(480,554)	(450,478)	(323,659)
Total revenues									(480,554)	(450,478)	(323,659)
Expenses:
Income before income (loss) from unconsolidated entities, income taxes, discontinued operations and noncontrolling interest									(480,554)	(450,478)	(323,659)
Income from continuing operations									(480,554)	(450,478)	(323,659)
Net income									(480,554)	(450,478)	(323,659)
Net income attributable to common stockholders									$ (480,554)	$ (450,478)	$ (323,659)