CONDENSED CONSOLIDATING INFORMATION (Unaudited) - Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Assets
Net real estate investments	$ 20,674,103	$ 20,637,904
Cash and cash equivalents	82,514	72,277
Escrow deposits and restricted cash	57,717	59,187
Investment in and advances to affiliates	0	0
Goodwill	1,050,876	1,050,548
Assets held for sale	5,978	5,454
Other assets	796,909	759,185
Total assets	22,668,097	22,584,555
Liabilities:
Senior notes payable and other debt	10,690,176	10,733,699
Intercompany loans	0	0
Accrued interest	81,766	99,667
Operating lease liabilities	214,046	0
Accounts payable and other liabilities	1,063,707	1,086,030
Liabilities related to assets held for sale	947	205
Deferred income taxes	205,056	205,219
Total liabilities	12,255,698	12,124,820
Redeemable OP unitholder and noncontrolling interests	206,386	188,141
Total equity	10,206,013	10,271,594	$ 10,804,044	$ 10,932,185
Total liabilities and equity	22,668,097	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	(18,359,851)	(18,382,790)
Goodwill	0	0
Assets held for sale	0	0
Other assets	0	0
Total assets	(18,359,851)	(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	(18,359,851)	(18,382,790)
Total liabilities and equity	(18,359,851)	(18,382,790)
Ventas, Inc.
Assets
Net real estate investments	3,561	3,598
Cash and cash equivalents	12,990	6,470
Escrow deposits and restricted cash	2,947	4,211
Investment in and advances to affiliates	15,633,653	15,656,592
Goodwill	0	0
Assets held for sale	0	0
Other assets	73,163	45,989
Total assets	15,726,314	15,716,860
Liabilities:
Senior notes payable and other debt	0	0
Intercompany loans	8,752,449	8,580,896
Accrued interest	(11,670)	(9,953)
Operating lease liabilities	12,541
Accounts payable and other liabilities	311,104	319,753
Liabilities related to assets held for sale	0	0
Deferred income taxes	608	608
Total liabilities	9,065,032	8,891,304
Redeemable OP unitholder and noncontrolling interests	15,257	13,746
Total equity	6,646,025	6,811,810
Total liabilities and equity	15,726,314	15,716,860
Ventas Realty
Assets
Net real estate investments	111,849	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	4,395	4,443
Total assets	2,842,570	2,843,460
Liabilities:
Senior notes payable and other debt	8,552,905	8,620,867
Intercompany loans	(5,490,449)	(5,629,764)
Accrued interest	71,560	85,717
Operating lease liabilities	521
Accounts payable and other liabilities	18,763	19,178
Liabilities related to assets held for sale	0	0
Deferred income taxes	0	0
Total liabilities	3,153,300	3,095,998
Redeemable OP unitholder and noncontrolling interests	0	0
Total equity	(310,730)	(252,538)
Total liabilities and equity	2,842,570	2,843,460
Ventas Subsidiaries
Assets
Net real estate investments	20,558,693	20,521,615
Cash and cash equivalents	69,524	65,807
Escrow deposits and restricted cash	54,642	54,848
Investment in and advances to affiliates	0	0
Goodwill	1,050,876	1,050,548
Assets held for sale	5,978	5,454
Other assets	719,351	708,753
Total assets	22,459,064	22,407,025
Liabilities:
Senior notes payable and other debt	2,137,271	2,112,832
Intercompany loans	(3,262,000)	(2,951,132)
Accrued interest	21,876	23,903
Operating lease liabilities	200,984
Accounts payable and other liabilities	733,840	747,099
Liabilities related to assets held for sale	947	205
Deferred income taxes	204,448	204,611
Total liabilities	37,366	137,518
Redeemable OP unitholder and noncontrolling interests	191,129	174,395
Total equity	22,230,569	22,095,112
Total liabilities and equity	$ 22,459,064	$ 22,407,025