Condensed Consolidating Information (Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
Rental income									$ 1,346,046	$ 1,138,457	$ 1,036,356
Resident fees and services									1,811,255	1,552,951	1,406,005
Medical office building and other services revenue									41,492	29,364	17,809
Income from loans and investments									86,553	51,778	54,425
Equity earnings in affiliates									0	0	0
Interest and other income									1,052	4,263	2,022
Total revenues	$ 841,274	$ 827,606	$ 811,920	$ 805,598	$ 732,090	$ 704,932	$ 674,529	$ 665,262	3,286,398	2,776,813	2,516,617
Expenses:
Interest									367,114	292,065	249,009
Depreciation and amortization									894,057	725,216	629,908
Property-level operating expenses									1,383,640	1,195,388	1,109,925
Medical office building services costs									26,565	17,092	8,315
General, administrative and professional fees									128,035	121,738	115,083
Loss on extinguishment of debt, net									14,411	5,564	1,201
Merger-related expenses and deal costs									102,944	43,304	21,634
Other									17,957	25,743	17,364
Total expenses									2,934,723	2,426,110	2,152,439
Income before loss from unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest									351,675	350,703	364,178
Loss from unconsolidated entities									(1,420)	(139)	(508)
Income tax benefit									39,284	8,732	11,828
Income from continuing operations									389,539	359,296	375,498
Discontinued operations	(2,331)	(22,383)	18,243	17,574	20,709	18,171	30,781	30,074	11,103	99,735	79,171
Gain on real estate dispositions									18,580	17,970	0
Net income									419,222	477,001	454,669
Net (loss) income attributable to noncontrolling interest, net of tax									1,379	1,234	1,160
Net income attributable to common stockholders	$ 124,728	$ 22,852	$ 149,821	$ 120,442	$ 107,190	$ 109,132	$ 138,398	$ 121,047	417,843	475,767	453,509
Consolidated Elimination
Revenues:
Equity earnings in affiliates									(459,545)	(480,466)	(450,348)
Total revenues									(459,545)	(480,466)	(450,348)
Expenses:
Income before loss from unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest									(459,545)	(480,466)	(450,348)
Income from continuing operations									(459,545)	(480,466)	(450,348)
Net income									(459,545)	(480,466)	(450,348)
Net income attributable to common stockholders									(459,545)	(480,466)	(450,348)
Ventas, Inc.
Revenues:
Rental income									3,663	2,789	2,486
Medical office building and other services revenue									895
Income from loans and investments									8,605	3,052	1,262
Equity earnings in affiliates									458,213	480,267	449,621
Interest and other income									495	3,314	2,963
Total revenues									471,871	489,422	456,332
Expenses:
Interest									(38,393)	(18,210)	(2,167)
Depreciation and amortization									5,443	5,860	4,990
Property-level operating expenses										1
General, administrative and professional fees									(321)	3,910	2,695
Loss on extinguishment of debt, net										(3)	3
Merger-related expenses and deal costs									98,644	26,209	11,917
Other									(358)	9,732	194
Total expenses									65,015	27,499	17,632
Income before loss from unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest									406,856	461,923	438,700
Income tax benefit									39,284	8,732	11,828
Income from continuing operations									446,140	470,655	450,528
Discontinued operations									(46,877)	(12,858)	2,981
Gain on real estate dispositions									18,580	17,970
Net income									417,843	475,767	453,509
Net income attributable to common stockholders									417,843	475,767	453,509
Ventas Realty
Revenues:
Rental income									198,017	180,907	171,953
Medical office building and other services revenue											(11)
Income from loans and investments									534		908
Interest and other income									(6)	26	26
Total revenues									198,545	180,933	172,876
Expenses:
Interest									257,503	185,983	144,327
Depreciation and amortization									14,679	15,743	17,248
Property-level operating expenses									367	481	514
General, administrative and professional fees									20,777	19,792	20,488
Loss on extinguishment of debt, net									4,523	3	1,510
Merger-related expenses and deal costs									75	2,110
Other									45		17
Total expenses									297,969	224,112	184,104
Income before loss from unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest									(99,424)	(43,179)	(11,228)
Loss from unconsolidated entities									(183)	1,250	673
Income from continuing operations									(99,607)	(41,929)	(10,555)
Discontinued operations									34,748	61,755	83,197
Net income									(64,859)	19,826	72,642
Net income attributable to common stockholders									$ (64,859)	19,826	72,642
Ownership percentage	100.00%								100.00%
Ventas Subsidiaries
Revenues:
Rental income									$ 1,144,366	954,761	861,917
Resident fees and services									1,811,255	1,552,951	1,406,005
Medical office building and other services revenue									40,597	29,364	17,820
Income from loans and investments									77,414	48,726	52,255
Equity earnings in affiliates									1,332	199	727
Interest and other income									563	923	(967)
Total revenues									3,075,527	2,586,924	2,337,757
Expenses:
Interest									148,004	124,292	106,849
Depreciation and amortization									873,935	703,613	607,670
Property-level operating expenses									1,383,273	1,194,906	1,109,411
Medical office building services costs									26,565	17,092	8,315
General, administrative and professional fees									107,579	98,036	91,900
Loss on extinguishment of debt, net									9,888	5,564	(312)
Merger-related expenses and deal costs									4,225	14,985	9,717
Other									18,270	16,011	17,153
Total expenses									2,571,739	2,174,499	1,950,703
Income before loss from unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest									503,788	412,425	387,054
Loss from unconsolidated entities									(1,237)	(1,389)	(1,181)
Income from continuing operations									502,551	411,036	385,873
Discontinued operations									23,232	50,838	(7,007)
Net income									525,783	461,874	378,866
Net (loss) income attributable to noncontrolling interest, net of tax									1,379	1,234	1,160
Net income attributable to common stockholders									$ 524,404	$ 460,640	$ 377,706
Ownership percentage		100.00%
Ventas Capital Corporation
Expenses:
Ownership percentage	100.00%				100.00%				100.00%	100.00%	100.00%