Condensed Consolidating Information (Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues
Rental income									$ 1,476,176	$ 1,346,046	$ 1,138,457
Resident fees and services									1,847,306	1,811,255	1,552,951
Office building and other services revenue									21,070	41,492	29,364
Income from loans and investments									98,094	86,553	51,778
Equity earnings in affiliates									0	0	0
Interest and other income									876	1,052	4,263
Total revenues	$ 875,713	$ 867,116	$ 848,404	$ 852,289	$ 841,274	$ 827,606	$ 811,920	$ 805,598	3,443,522	3,286,398	2,776,813
Expenses
Interest									419,740	367,114	292,065
Depreciation and amortization									898,924	894,057	725,216
Property-level operating expenses									1,434,762	1,383,640	1,195,388
Office building services costs									7,311	26,565	17,092
General, administrative and professional fees									126,875	128,035	121,738
Loss on extinguishment of debt, net									2,779	14,411	5,564
Merger-related expenses and deal costs									24,635	102,944	43,304
Other									9,988	17,957	25,743
Total expenses									2,925,014	2,934,723	2,426,110
Income before unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest									518,508	351,675	350,703
Income (loss) from unconsolidated entities									4,358	(1,420)	(139)
Income tax benefit									31,343	39,284	8,732
Income from continuing operations									554,209	389,539	359,296
Discontinued operations	(167)	(118)	(148)	(489)	(2,331)	(22,383)	18,243	17,574	(922)	11,103	99,735
Gain on real estate dispositions									98,203	18,580	17,970
Net income									651,490	419,222	477,001
Net (loss) income attributable to noncontrolling interest, net of tax									2,259	1,379	1,234
Net income attributable to common stockholders	$ 207,637	$ 149,452	$ 143,162	$ 148,980	$ 124,728	$ 22,852	$ 149,821	$ 120,442	649,231	417,843	475,767
Consolidated Elimination
Revenues
Equity earnings in affiliates									(499,292)	(457,564)	(480,466)
Total revenues									(499,292)	(457,564)	(480,466)
Expenses
Income before unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest									(499,292)	(457,564)	(480,466)
Income from continuing operations									(499,292)	(457,564)	(480,466)
Net income									(499,292)	(457,564)	(480,466)
Net income attributable to common stockholders									(499,292)	(457,564)	(480,466)
Ventas, Inc.
Revenues
Rental income									2,670	3,663	2,789
Office building and other services revenue									1,605	895
Income from loans and investments									341	8,605	3,052
Equity earnings in affiliates									500,515	458,213	480,267
Interest and other income									666	495	3,314
Total revenues									505,797	471,871	489,422
Expenses
Interest									(46,650)	(38,393)	(18,210)
Depreciation and amortization									8,968	5,443	5,860
Property-level operating expenses											1
General, administrative and professional fees									509	(321)	3,910
Loss on extinguishment of debt, net											(3)
Merger-related expenses and deal costs									23,068	98,644	26,209
Other									(705)	(358)	9,732
Total expenses									(14,810)	65,015	27,499
Income before unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest									520,607	406,856	461,923
Income tax benefit									31,343	39,284	8,732
Income from continuing operations									551,950	446,140	470,655
Discontinued operations									(922)	(46,877)	(12,858)
Gain on real estate dispositions									98,203	18,580	17,970
Net income									649,231	417,843	475,767
Net income attributable to common stockholders									649,231	417,843	475,767
Ventas Realty
Revenues
Rental income									196,991	198,017	180,907
Income from loans and investments										534
Interest and other income										(6)	26
Total revenues									196,991	198,545	180,933
Expenses
Interest									281,458	257,503	185,983
Depreciation and amortization									18,297	14,679	15,743
Property-level operating expenses									317	367	481
General, administrative and professional fees									18,320	20,777	19,792
Loss on extinguishment of debt, net									2,770	4,523	3
Merger-related expenses and deal costs										75	2,110
Other									41	45
Total expenses									321,203	297,969	224,112
Income before unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest									(124,212)	(99,424)	(43,179)
Income (loss) from unconsolidated entities									1,840	(183)	1,250
Income from continuing operations									(122,372)	(99,607)	(41,929)
Discontinued operations										34,748	61,755
Net income									(122,372)	(64,859)	19,826
Net income attributable to common stockholders									(122,372)	(64,859)	19,826
Ventas Subsidiaries
Revenues
Rental income									1,276,515	1,144,366	954,761
Resident fees and services									1,847,306	1,811,255	1,552,951
Office building and other services revenue									19,465	40,597	29,364
Income from loans and investments									97,753	77,414	48,726
Equity earnings in affiliates									(1,223)	(649)	199
Interest and other income									210	563	923
Total revenues									3,240,026	3,073,546	2,586,924
Expenses
Interest									184,932	148,004	124,292
Depreciation and amortization									871,659	873,935	703,613
Property-level operating expenses									1,434,445	1,383,273	1,194,906
Office building services costs									7,311	26,565	17,092
General, administrative and professional fees									108,046	107,579	98,036
Loss on extinguishment of debt, net									9	9,888	5,564
Merger-related expenses and deal costs									1,567	4,225	14,985
Other									10,652	18,270	16,011
Total expenses									2,618,621	2,571,739	2,174,499
Income before unconsolidated entities, income taxes, discontinued operations, real estate dispositions and noncontrolling interest									621,405	501,807	412,425
Income (loss) from unconsolidated entities									2,518	(1,237)	(1,389)
Income from continuing operations									623,923	500,570	411,036
Discontinued operations										23,232	50,838
Net income									623,923	523,802	461,874
Net (loss) income attributable to noncontrolling interest, net of tax									2,259	1,379	1,234
Net income attributable to common stockholders									$ 621,664	$ 522,423	$ 460,640