CONDENSED CONSOLIDATING INFORMATION - Statement of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Condensed financial statements, captions
Net income (loss)	$ 23,117	$ 109,654	$ 294,162	$ 369,404	$ 477,186
Other comprehensive income (loss):
Foreign currency translation	(11,239)	(12,885)	(7,718)	(7,906)
Change in unrealized gain on marketable securities	0	(334)	(5,046)	1,237
Other	467	3,120	(949)	3,166
Total other comprehensive loss	(10,772)	(10,099)	(13,713)	(3,503)	$ (6,538)
Comprehensive income	12,345	99,555	280,449	365,901
Comprehensive income attributable to noncontrolling interest	265	522	1,047	827
Comprehensive income attributable to common stockholders	12,080	99,033	279,402	365,074
Ventas, Inc.
Condensed financial statements, captions
Net income (loss)	22,852	109,132	293,115	368,577
Other comprehensive income (loss):
Foreign currency translation	0	0	0	0
Change in unrealized gain on marketable securities		(334)	(5,046)	1,237
Other	0	0	0	0
Total other comprehensive loss	0	(334)	(5,046)	1,237
Comprehensive income	22,852	108,798	288,069	369,814
Comprehensive income attributable to noncontrolling interest	0	0	0	0
Comprehensive income attributable to common stockholders	22,852	108,798	288,069	369,814
Ventas Realty
Condensed financial statements, captions
Net income (loss)	(24,305)	2,230	(38,333)	18,687
Other comprehensive income (loss):
Foreign currency translation	0	0	0	0
Change in unrealized gain on marketable securities		0	0	0
Other	0	0	0	0
Total other comprehensive loss	0	0	0	0
Comprehensive income	(24,305)	2,230	(38,333)	18,687
Comprehensive income attributable to noncontrolling interest	0	0	0	0
Comprehensive income attributable to common stockholders	$ (24,305)	$ 2,230	$ (38,333)	$ 18,687
Ownership percentage	100.00%		100.00%
Ventas Capital Corporation
Other comprehensive income (loss):
Ownership percentage	100.00%	100.00%	100.00%	100.00%	100.00%
Ventas Subsidiaries
Condensed financial statements, captions
Net income (loss)	$ 124,200	$ 123,052	$ 399,985	$ 365,572
Other comprehensive income (loss):
Foreign currency translation	(11,239)	(12,885)	(7,718)	(7,906)
Change in unrealized gain on marketable securities		0	0	0
Other	467	3,120	(949)	3,166
Total other comprehensive loss	(10,772)	(9,765)	(8,667)	(4,740)
Comprehensive income	113,428	113,287	391,318	360,832
Comprehensive income attributable to noncontrolling interest	265	522	1,047	827
Comprehensive income attributable to common stockholders	113,163	112,765	390,271	360,005
Consolidated Eliminations
Condensed financial statements, captions
Net income (loss)	(99,630)	(124,760)	(360,605)	(383,432)
Other comprehensive income (loss):
Foreign currency translation	0	0	0	0
Change in unrealized gain on marketable securities		0	0	0
Other	0	0	0	0
Total other comprehensive loss	0	0	0	0
Comprehensive income	(99,630)	(124,760)	(360,605)	(383,432)
Comprehensive income attributable to noncontrolling interest	0	0	0	0
Comprehensive income attributable to common stockholders	$ (99,630)	$ (124,760)	$ (360,605)	$ (383,432)