CONDENSED CONSOLIDATING INFORMATION - Statement of Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Revenues:
Rental income	$ 343,783	$ 287,559	$ 991,878	$ 846,989
Resident fees and services	454,825	396,247	1,356,384	1,141,781
Medical office building and other services revenue	10,000	7,573	29,951	18,240
Income from loans and investments	18,924	13,186	66,192	36,902
Equity earnings in affiliates	0	0	0	0
Interest and other income	74	367	719	811
Total revenues	827,606	704,932	2,445,124	2,044,723
Expenses:
Interest	97,135	77,325	263,422	214,117
Depreciation and amortization	226,332	173,006	657,262	507,167
Property-level operating expenses	347,845	306,536	1,031,306	883,014
Medical office building services costs	6,416	4,568	19,098	9,565
General, administrative and professional fees	32,114	29,464	100,399	93,632
(Gain) loss on extinguishment of debt, net	15,331	2,414	14,897	5,079
Merger-related expenses and deal costs	62,145	16,188	105,023	35,944
Other	4,795	9,413	13,948	18,070
Total expenses	792,113	618,914	2,205,355	1,766,588
Income before (loss) income from unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest	35,493	86,018	239,769	278,135
Income (loss) from unconsolidated entities	(955)	(47)	(1,197)	549
Income tax benefit (expense)	10,697	1,887	27,736	(4,820)
Income from continuing operations	45,235	87,858	266,308	273,864
Discontinued operations	(22,383)	18,171	13,434	79,026
Gain on real estate dispositions	265	3,625	14,420	16,514
Net income	23,117	109,654	294,162	369,404	$ 477,186
Net income attributable to noncontrolling interest	265	522	1,047	827
Net income attributable to common stockholders	22,852	109,132	293,115	368,577
Ventas, Inc.
Revenues:
Rental income	916	626	2,747	1,873
Resident fees and services	0	0	0	0
Medical office building and other services revenue	293	0	293	0
Income from loans and investments	50	1,049	8,655	2,285
Equity earnings in affiliates	99,873	124,738	360,988	383,245
Interest and other income	106	109	482	294
Total revenues	101,238	126,522	373,165	387,697
Expenses:
Interest	(10,788)	(6,199)	(27,548)	(11,071)
Depreciation and amortization	1,347	1,489	4,047	4,387
Property-level operating expenses	0	0	0	0
Medical office building services costs	0	0	0	0
General, administrative and professional fees	(678)	1,147	(598)	3,022
(Gain) loss on extinguishment of debt, net	0	0	0	(3)
Merger-related expenses and deal costs	62,007	13,403	101,306	21,035
Other	271	6,932	453	7,055
Total expenses	52,159	16,772	77,660	24,425
Income before (loss) income from unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest	49,079	109,750	295,505	363,272
Income (loss) from unconsolidated entities	0	0	0	0
Income tax benefit (expense)	10,697	1,887	27,736	(4,820)
Income from continuing operations	59,776	111,637	323,241	358,452
Discontinued operations	(37,189)	(6,130)	(44,546)	(6,389)
Gain on real estate dispositions	265	3,625	14,420	16,514
Net income	22,852	109,132	293,115	368,577
Net income attributable to noncontrolling interest	0	0	0	0
Net income attributable to common stockholders	$ 22,852	109,132	$ 293,115	368,577
Ventas Realty
Condensed financial statements, captions
Ownership percentage	100.00%		100.00%
Revenues:
Rental income	$ 49,425	44,873	$ 148,833	133,346
Resident fees and services	0	0	0	0
Medical office building and other services revenue	0	0	0	0
Income from loans and investments	180	0	483	0
Equity earnings in affiliates	0	0	0	0
Interest and other income	(2)	10	(6)	21
Total revenues	49,603	44,883	149,310	133,367
Expenses:
Interest	67,521	49,011	189,716	133,215
Depreciation and amortization	3,455	3,831	11,394	11,839
Property-level operating expenses	81	141	285	388
Medical office building services costs	0	0	0	0
General, administrative and professional fees	5,225	5,067	16,640	15,975
(Gain) loss on extinguishment of debt, net	4,523	0	4,523	3
Merger-related expenses and deal costs	0	0	75	2,110
Other	5	0	49
Total expenses	80,810	58,050	222,682	163,530
Income before (loss) income from unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest	(31,207)	(13,167)	(73,372)	(30,163)
Income (loss) from unconsolidated entities	(469)	315	291	1,156
Income tax benefit (expense)	0	0	0	0
Income from continuing operations	(31,676)	(12,852)	(73,081)	(29,007)
Discontinued operations	7,371	15,082	34,748	47,694
Gain on real estate dispositions	0	0	0	0
Net income	(24,305)	2,230	(38,333)	18,687
Net income attributable to noncontrolling interest	0	0	0	0
Net income attributable to common stockholders	$ (24,305)	$ 2,230	$ (38,333)	$ 18,687
Ventas Capital Corporation
Condensed financial statements, captions
Ownership percentage	100.00%	100.00%	100.00%	100.00%	100.00%
Ventas Subsidiaries
Revenues:
Rental income	$ 293,442	$ 242,060	$ 840,298	$ 711,770
Resident fees and services	454,825	396,247	1,356,384	1,141,781
Medical office building and other services revenue	9,707	7,573	29,658	18,240
Income from loans and investments	18,694	12,137	57,054	34,617
Equity earnings in affiliates	(243)	22	(383)	187
Interest and other income	(30)	248	243	496
Total revenues	776,395	658,287	2,283,254	1,907,091
Expenses:
Interest	40,402	34,513	101,254	91,973
Depreciation and amortization	221,530	167,686	641,821	490,941
Property-level operating expenses	347,764	306,395	1,031,021	882,626
Medical office building services costs	6,416	4,568	19,098	9,565
General, administrative and professional fees	27,567	23,250	84,357	74,635
(Gain) loss on extinguishment of debt, net	10,808	2,414	10,374	5,079
Merger-related expenses and deal costs	138	2,785	3,642	12,799
Other	4,519	2,481	13,446	11,015
Total expenses	659,144	544,092	1,905,013	1,578,633
Income before (loss) income from unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest	117,251	114,195	378,241	328,458
Income (loss) from unconsolidated entities	(486)	(362)	(1,488)	(607)
Income tax benefit (expense)	0	0	0	0
Income from continuing operations	116,765	113,833	376,753	327,851
Discontinued operations	7,435	9,219	23,232	37,721
Gain on real estate dispositions	0	0	0	0
Net income	124,200	123,052	399,985	365,572
Net income attributable to noncontrolling interest	265	522	1,047	827
Net income attributable to common stockholders	123,935	122,530	398,938	364,745
Consolidated Eliminations
Revenues:
Rental income	0	0	0	0
Resident fees and services	0	0	0	0
Medical office building and other services revenue	0	0	0	0
Income from loans and investments	0	0	0	0
Equity earnings in affiliates	(99,630)	(124,760)	(360,605)	(383,432)
Interest and other income	0	0	0	0
Total revenues	(99,630)	(124,760)	(360,605)	(383,432)
Expenses:
Interest	0	0	0	0
Depreciation and amortization	0	0	0	0
Property-level operating expenses	0	0	0	0
Medical office building services costs	0	0	0	0
General, administrative and professional fees	0	0	0	0
(Gain) loss on extinguishment of debt, net	0	0	0	0
Merger-related expenses and deal costs	0	0	0	0
Other	0	0	0	0
Total expenses	0	0	0	0
Income before (loss) income from unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest	(99,630)	(124,760)	(360,605)	(383,432)
Income (loss) from unconsolidated entities	0	0	0	0
Income tax benefit (expense)	0	0	0	0
Income from continuing operations	(99,630)	(124,760)	(360,605)	(383,432)
Discontinued operations	0	0	0	0
Gain on real estate dispositions	0	0	0	0
Net income	(99,630)	(124,760)	(360,605)	(383,432)
Net income attributable to noncontrolling interest	0	0	0	0
Net income attributable to common stockholders	$ (99,630)	$ (124,760)	$ (360,605)	$ (383,432)