CONDENSED CONSOLIDATING INFORMATION (Unaudited) - Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Assets
Net real estate investments	$ 22,687,657		$ 20,637,904
Cash and cash equivalents	148,063		72,277
Escrow deposits and restricted cash	60,533		59,187
Investment in and advances to affiliates	0		0
Goodwill	1,049,985		1,050,548
Assets held for sale	4,520		5,454
Other assets	852,795		759,185
Total assets	24,803,553		22,584,555
Liabilities:
Senior notes payable and other debt	12,053,184		10,733,699
Intercompany loans	0		0
Accrued interest	85,214		99,667
Operating lease liabilities	249,237		0
Accounts payable and other liabilities	1,194,162		1,086,030
Liabilities related to assets held for sale	1,531		205
Deferred income taxes	147,524		205,219
Total liabilities	13,730,852		12,124,820
Redeemable OP unitholder and noncontrolling interests	236,792		188,141
Total equity	10,835,909	$ 10,876,362	10,271,594	$ 10,513,069	$ 10,677,569	$ 10,932,185
Total liabilities and equity	24,803,553		22,584,555
Consolidated Elimination
Assets
Net real estate investments	0		0
Cash and cash equivalents	0		0
Escrow deposits and restricted cash	0		0
Investment in and advances to affiliates	(18,621,808)		(18,382,790)
Goodwill	0		0
Assets held for sale	0		0
Other assets	0		0
Total assets	(18,621,808)		(18,382,790)
Liabilities:
Senior notes payable and other debt	0		0
Intercompany loans	0		0
Accrued interest	0		0
Operating lease liabilities	0
Accounts payable and other liabilities	0		0
Liabilities related to assets held for sale	0		0
Deferred income taxes	0		0
Total liabilities	0		0
Redeemable OP unitholder and noncontrolling interests	0		0
Total equity	(18,621,808)		(18,382,790)
Total liabilities and equity	(18,621,808)		(18,382,790)
Ventas, Inc.
Assets
Net real estate investments	3,488		3,598
Cash and cash equivalents	17,632		6,470
Escrow deposits and restricted cash	1,328		4,211
Investment in and advances to affiliates	15,895,610		15,656,592
Goodwill	0		0
Assets held for sale	0		0
Other assets	92,361		45,989
Total assets	16,010,419		15,716,860
Liabilities:
Senior notes payable and other debt	0		0
Intercompany loans	8,741,304		8,580,896
Accrued interest	(13,265)		(9,953)
Operating lease liabilities	11,285
Accounts payable and other liabilities	333,433		319,753
Liabilities related to assets held for sale	0		0
Deferred income taxes	608		608
Total liabilities	9,073,365		8,891,304
Redeemable OP unitholder and noncontrolling interests	18,433		13,746
Total equity	6,918,621		6,811,810
Total liabilities and equity	16,010,419		15,716,860
Ventas Realty
Assets
Net real estate investments	109,211		112,691
Cash and cash equivalents	0		0
Escrow deposits and restricted cash	128		128
Investment in and advances to affiliates	2,726,198		2,726,198
Goodwill	0		0
Assets held for sale	0		0
Other assets	2,198		4,443
Total assets	2,837,735		2,843,460
Liabilities:
Senior notes payable and other debt	8,256,489		8,620,867
Intercompany loans	(5,038,388)		(5,629,764)
Accrued interest	72,477		85,717
Operating lease liabilities	520
Accounts payable and other liabilities	22,084		19,178
Liabilities related to assets held for sale	569		0
Deferred income taxes	0		0
Total liabilities	3,313,751		3,095,998
Redeemable OP unitholder and noncontrolling interests	0		0
Total equity	(476,016)		(252,538)
Total liabilities and equity	2,837,735		2,843,460
Ventas Subsidiaries
Assets
Net real estate investments	22,574,958		20,521,615
Cash and cash equivalents	130,431		65,807
Escrow deposits and restricted cash	59,077		54,848
Investment in and advances to affiliates	0		0
Goodwill	1,049,985		1,050,548
Assets held for sale	4,520		5,454
Other assets	758,236		708,753
Total assets	24,577,207		22,407,025
Liabilities:
Senior notes payable and other debt	3,796,695		2,112,832
Intercompany loans	(3,702,916)		(2,951,132)
Accrued interest	26,002		23,903
Operating lease liabilities	237,432
Accounts payable and other liabilities	838,645		747,099
Liabilities related to assets held for sale	962		205
Deferred income taxes	146,916		204,611
Total liabilities	1,343,736		137,518
Redeemable OP unitholder and noncontrolling interests	218,359		174,395
Total equity	23,015,112		22,095,112
Total liabilities and equity	$ 24,577,207		$ 22,407,025