CONDENSED CONSOLIDATING INFORMATION - Statement of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Mar. 31, 2015
Condensed financial statements, captions
Net income (loss)	$ 143,440	$ 150,286	$ 292,474	$ 271,045	$ 419,222
Other comprehensive income (loss):
Foreign currency translation	(22,715)	14,393	(33,383)	3,521
Change in unrealized gain on marketable securities	69	(6,395)	250	(5,046)
Other	(1,617)	(2,175)	(3,497)	(1,416)
Total other comprehensive (loss) income	(24,263)	5,823	(36,630)	(2,941)	$ (20,686)
Comprehensive income	119,177	156,109	255,844	268,104
Comprehensive income attributable to noncontrolling interest	278	465	332	782
Comprehensive income attributable to common stockholders	118,899	155,644	255,512	267,322
Consolidated Elimination
Condensed financial statements, captions
Net income (loss)	(123,740)	(131,058)	(232,159)	(260,975)
Other comprehensive income (loss):
Foreign currency translation	0	0	0	0
Change in unrealized gain on marketable securities	0	0	0	0
Other	0	0	0	0
Total other comprehensive (loss) income	0	0	0	0
Comprehensive income	(123,740)	(131,058)	(232,159)	(260,975)
Comprehensive income attributable to noncontrolling interest	0	0	0	0
Comprehensive income attributable to common stockholders	(123,740)	(131,058)	(232,159)	(260,975)
Ventas, Inc.
Condensed financial statements, captions
Net income (loss)	143,162	149,821	292,142	270,263
Other comprehensive income (loss):
Foreign currency translation	0	0	0	0
Change in unrealized gain on marketable securities	69	(6,395)	250	(5,046)
Other	0	0	0	0
Total other comprehensive (loss) income	69	(6,395)	250	(5,046)
Comprehensive income	143,231	143,426	292,392	265,217
Comprehensive income attributable to noncontrolling interest	0	0	0	0
Comprehensive income attributable to common stockholders	143,231	143,426	292,392	265,217
Ventas Realty
Condensed financial statements, captions
Net income (loss)	(28,842)	(6,231)	(63,090)	(14,025)
Other comprehensive income (loss):
Foreign currency translation	0	0	0	0
Change in unrealized gain on marketable securities	0	0	0	0
Other	0	0	0	0
Total other comprehensive (loss) income	0	0	0	0
Comprehensive income	(28,842)	(6,231)	(63,090)	(14,025)
Comprehensive income attributable to noncontrolling interest	0	0	0	0
Comprehensive income attributable to common stockholders	$ (28,842)	(6,231)	$ (63,090)	(14,025)
Ownership percentage	100.00%		100.00%
Ventas Subsidiaries
Condensed financial statements, captions
Net income (loss)	$ 152,860	137,754	$ 295,581	275,782
Other comprehensive income (loss):
Foreign currency translation	(22,715)	14,393	(33,383)	3,521
Change in unrealized gain on marketable securities	0	0	0	0
Other	(1,617)	(2,175)	(3,497)	(1,416)
Total other comprehensive (loss) income	(24,332)	12,218	(36,880)	2,105
Comprehensive income	128,528	149,972	258,701	277,887
Comprehensive income attributable to noncontrolling interest	278	465	332	782
Comprehensive income attributable to common stockholders	$ 128,250	$ 149,507	$ 258,369	$ 277,105
Ventas Capital Corporation
Other comprehensive income (loss):
Ownership percentage	100.00%	100.00%	100.00%	100.00%	100.00%	100.00%