CONDENSED CONSOLIDATING INFORMATION (Unaudited) - Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Condensed financial statements, captions
Deferred income taxes	$ 296,272	$ 316,641
Assets
Net real estate investments	21,934,492	21,192,696
Cash and cash equivalents	85,063	286,707	$ 89,279	$ 53,023
Escrow deposits and restricted cash	76,522	80,647
Investment in and advances to affiliates	0	0
Goodwill	1,034,497	1,033,225
Assets held for sale	68,926	54,961
Other assets	540,295	518,364
Total assets	23,739,795	23,166,600
Liabilities:
Senior notes payable and other debt	11,424,145	11,127,326
Intercompany loans	0	0
Accrued interest	95,684	83,762
Accounts payable and other liabilities	943,800	907,928
Liabilities related to assets held for sale	9,837	1,462
Total liabilities	12,769,738	12,437,119
Redeemable OP unitholder and noncontrolling interests	171,813	200,728
Total equity	10,798,244	10,528,753		9,625,427
Total liabilities and equity	23,739,795	23,166,600
Consolidated Elimination
Condensed financial statements, captions
Deferred income taxes	0	0
Assets
Net real estate investments	0	0
Cash and cash equivalents	0	0	0	0
Escrow deposits and restricted cash	0	0
Investment in and advances to affiliates	(17,522,512)	(17,197,372)
Goodwill	0	0
Assets held for sale	0	0
Other assets	0	0
Total assets	(17,522,512)	(17,197,372)
Liabilities:
Senior notes payable and other debt	0	0
Intercompany loans	0	0
Accrued interest	0	0
Accounts payable and other liabilities	0	0
Liabilities related to assets held for sale	0	0
Total liabilities	0	0
Redeemable OP unitholder and noncontrolling interests	0	0
Total equity	(17,522,512)	(17,197,372)
Total liabilities and equity	(17,522,512)	(17,197,372)
Ventas, Inc.
Condensed financial statements, captions
Deferred income taxes	296,272	316,641
Assets
Net real estate investments	1,881	2,007
Cash and cash equivalents	14,063	210,303	12,039	11,733
Escrow deposits and restricted cash	197	198
Investment in and advances to affiliates	14,606,452	14,258,931
Goodwill	0	0
Assets held for sale	0	0
Other assets	44,166	35,468
Total assets	14,666,759	14,506,907
Liabilities:
Senior notes payable and other debt	0	0
Intercompany loans	7,666,742	7,088,838
Accrued interest	(6,686)	(1,753)
Accounts payable and other liabilities	130,732	89,115
Liabilities related to assets held for sale	0	0
Total liabilities	8,087,060	7,492,841
Redeemable OP unitholder and noncontrolling interests	0	0
Total equity	6,579,699	7,014,066
Total liabilities and equity	14,666,759	14,506,907
Ventas Realty
Condensed financial statements, captions
Deferred income taxes	$ 0	0
Ownership percentage by parent	100.00%
Assets
Net real estate investments	$ 121,240	173,259
Cash and cash equivalents	0	0		0
Escrow deposits and restricted cash	128	1,504
Investment in and advances to affiliates	2,916,060	2,938,441
Goodwill	0	0
Assets held for sale	12,757	0
Other assets	7,606	6,792
Total assets	3,057,791	3,119,996
Liabilities:
Senior notes payable and other debt	8,883,519	8,406,979
Intercompany loans	(6,958,293)	(6,209,707)
Accrued interest	83,604	67,156
Accounts payable and other liabilities	22,280	35,587
Liabilities related to assets held for sale	7,666	(1)
Total liabilities	2,038,776	2,300,014
Redeemable OP unitholder and noncontrolling interests	0	0
Total equity	1,019,015	819,982
Total liabilities and equity	3,057,791	3,119,996
Ventas Subsidiaries
Condensed financial statements, captions
Deferred income taxes	0	0
Assets
Net real estate investments	21,811,371	21,017,430
Cash and cash equivalents	71,000	76,404	$ 77,240	$ 41,290
Escrow deposits and restricted cash	76,197	78,945
Investment in and advances to affiliates	0	0
Goodwill	1,034,497	1,033,225
Assets held for sale	56,169	54,961
Other assets	488,523	476,104
Total assets	23,537,757	22,737,069
Liabilities:
Senior notes payable and other debt	2,540,626	2,720,347
Intercompany loans	(708,449)	(879,131)
Accrued interest	18,766	18,359
Accounts payable and other liabilities	790,788	783,226
Liabilities related to assets held for sale	2,171	1,463
Total liabilities	2,643,902	2,644,264
Redeemable OP unitholder and noncontrolling interests	171,813	200,728
Total equity	20,722,042	19,892,077
Total liabilities and equity	23,537,757	$ 22,737,069
Ventas Capital Corporation
Assets
Total assets	$ 0
Nationwide Health Properties
Condensed financial statements, captions
Ownership percentage by parent	100.00%