CONDENSED CONSOLIDATING INFORMATION - Statement of Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Mar. 31, 2015
Revenues:
Rental income	$ 354,206	$ 322,478	$ 712,829	$ 648,095
Resident fees and services	464,437	454,645	928,413	901,559
Medical office building and other services revenue	5,504	9,408	12,689	19,951
Income from loans and investments	24,146	25,215	46,532	47,268
Equity earnings in affiliates	0	0	0	0
Interest and other income	111	174	230	645
Total revenues	848,404	811,920	1,700,693	1,617,518
Expenses:
Interest	103,665	83,959	206,938	166,287
Depreciation and amortization	221,961	214,711	458,348	430,930
Property-level operating expenses	351,955	342,662	708,177	683,461
Medical office building services costs	1,852	5,764	5,303	12,682
General, administrative and professional fees	32,094	33,959	63,820	68,285
(Gain) loss on extinguishment of debt, net	2,468	(455)	2,782	(434)
Merger-related expenses and deal costs	7,224	12,265	8,856	42,878
Other	2,303	4,279	6,471	9,153
Total expenses	723,522	697,144	1,460,695	1,413,242
Income before unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest	124,882	114,776	239,998	204,276
Income (loss) from unconsolidated entities	1,418	9	1,220	(242)
Income tax benefit	11,549	9,789	19,970	17,039
Income from continuing operations	137,849	124,574	261,188	221,073
Discontinued operations	(148)	18,243	(637)	35,817
Gain on real estate dispositions	5,739	7,469	31,923	14,155
Net income	143,440	150,286	292,474	271,045	$ 419,222
Net income attributable to noncontrolling interest	278	465	332	782
Net income attributable to common stockholders	143,162	149,821	292,142	270,263
Consolidated Elimination
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	(123,740)	(131,058)	(232,159)	(260,975)
Interest and other income	0	0	0	0
Total revenues	(123,740)	(131,058)	(232,159)	(260,975)
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 unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest	(123,740)	(131,058)	(232,159)	(260,975)
Income (loss) from unconsolidated entities	0	0	0	0
Income tax benefit	0	0	0	0
Income from continuing operations	(123,740)	(131,058)	(232,159)	(260,975)
Discontinued operations	0	0	0	0
Gain on real estate dispositions	0	0	0	0
Net income	(123,740)	(131,058)	(232,159)	(260,975)
Net income attributable to noncontrolling interest	0	0	0	0
Net income attributable to common stockholders	(123,740)	(131,058)	(232,159)	(260,975)
Ventas, Inc.
Revenues:
Rental income	583	914	1,499	1,831
Resident fees and services	0	0	0	0
Medical office building and other services revenue	602	0	1,204	0
Income from loans and investments	0	7,169	0	8,605
Equity earnings in affiliates	124,028	131,120	232,790	261,115
Interest and other income	41	20	70	376
Total revenues	125,254	139,223	235,563	271,927
Expenses:
Interest	(11,094)	(8,932)	(21,889)	(16,760)
Depreciation and amortization	1,203	1,357	6,135	2,700
Property-level operating expenses	0	0	0	0
Medical office building services costs	0	0	0	0
General, administrative and professional fees	2,246	2,822	2,231	80
(Gain) loss on extinguishment of debt, net	58	0	58	0
Merger-related expenses and deal costs	6,743	9,506	8,115	39,299
Other	76	(465)	27	182
Total expenses	(768)	4,288	(5,323)	25,501
Income before unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest	126,022	134,935	240,886	246,426
Income (loss) from unconsolidated entities	0	0	0	0
Income tax benefit	11,549	9,789	19,970	17,039
Income from continuing operations	137,571	144,724	260,856	263,465
Discontinued operations	(148)	(2,372)	(637)	(7,357)
Gain on real estate dispositions	5,739	7,469	31,923	14,155
Net income	143,162	149,821	292,142	270,263
Net income attributable to noncontrolling interest	0	0	0	0
Net income attributable to common stockholders	$ 143,162	149,821	$ 292,142	270,263
Ventas Realty
Condensed financial statements, captions
Ownership percentage	100.00%		100.00%
Revenues:
Rental income	$ 49,418	49,620	$ 98,143	99,408
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	252	0	303
Equity earnings in affiliates	0	0	0	0
Interest and other income	0
Total revenues	49,418	49,872	98,143	99,711
Expenses:
Interest	69,011	61,572	137,590	122,195
Depreciation and amortization	2,867	3,505	12,781	7,939
Property-level operating expenses	77	73	156	204
Medical office building services costs	0	0	0	0
General, administrative and professional fees	4,213	5,054	8,717	11,415
(Gain) loss on extinguishment of debt, net	2,432	0	2,432	0
Merger-related expenses and deal costs	0	75	0	75
Other	4	40	4	45
Total expenses	78,604	70,319	161,680	141,873
Income before unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest	(29,186)	(20,447)	(63,537)	(42,162)
Income (loss) from unconsolidated entities	344	359	447	760
Income tax benefit	0	0	0	0
Income from continuing operations	(28,842)	(20,088)	(63,090)	(41,402)
Discontinued operations	0	13,857		27,377
Gain on real estate dispositions	0	0	0	0
Net income	(28,842)	(6,231)	(63,090)	(14,025)
Net income attributable to noncontrolling interest	0	0	0	0
Net income attributable to common stockholders	(28,842)	(6,231)	(63,090)	(14,025)
Ventas Subsidiaries
Revenues:
Rental income	304,205	271,944	613,187	546,856
Resident fees and services	464,437	454,645	928,413	901,559
Medical office building and other services revenue	4,902	9,408	11,485	19,951
Income from loans and investments	24,146	17,794	46,532	38,360
Equity earnings in affiliates	(288)	(62)	(631)	(140)
Interest and other income	70	154	160	269
Total revenues	797,472	753,883	1,599,146	1,506,855
Expenses:
Interest	45,748	31,319	91,237	60,852
Depreciation and amortization	217,891	209,849	439,432	420,291
Property-level operating expenses	351,878	342,589	708,021	683,257
Medical office building services costs	1,852	5,764	5,303	12,682
General, administrative and professional fees	25,635	26,083	52,872	56,790
(Gain) loss on extinguishment of debt, net	(22)	(455)	292	(434)
Merger-related expenses and deal costs	481	2,684	741	3,504
Other	2,223	4,704	6,440	8,926
Total expenses	645,686	622,537	1,304,338	1,245,868
Income before unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest	151,786	131,346	294,808	260,987
Income (loss) from unconsolidated entities	1,074	(350)	773	(1,002)
Income tax benefit	0	0	0	0
Income from continuing operations	152,860	130,996	295,581	259,985
Discontinued operations	0	6,758		15,797
Gain on real estate dispositions	0	0	0	0
Net income	152,860	137,754	295,581	275,782
Net income attributable to noncontrolling interest	278	465	332	782
Net income attributable to common stockholders	$ 152,582	$ 137,289	$ 295,249	$ 275,000
Ventas Capital Corporation
Condensed financial statements, captions
Ownership percentage	100.00%	100.00%	100.00%	100.00%	100.00%	100.00%