Condensed Consolidating Information (Comprehensive Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Net income	$ 63,302	$ 103,281	$ 169,300	$ 80,098	$ 393,805	$ 615,191	$ 152,968	$ 199,148	$ 415,981	$ 1,361,112	$ 651,490
Other comprehensive income (loss):
Foreign currency translation									(9,436)	20,612	(52,266)
Unrealized gain (loss) on marketable debt securities									14,944	(437)	(310)
Derivative instruments									10,030	2,239	2,607
Total other comprehensive income (loss)									15,538	22,414	(49,969)
Comprehensive income									431,519	1,383,526	601,521
Comprehensive income attributable to noncontrolling interests									6,514	4,642	2,259
Comprehensive income attributable to common stockholders									425,005	1,378,884	599,262
Consolidated Elimination
Condensed Financial Statements, Captions [Line Items]
Net income									(306,068)	(1,265,751)	(626,041)
Other comprehensive income (loss):
Foreign currency translation									0	0	0
Unrealized gain (loss) on marketable debt securities									0	0	0
Derivative instruments									0	0	0
Total other comprehensive income (loss)									0	0	0
Comprehensive income									(306,068)	(1,265,751)	(626,041)
Comprehensive income attributable to noncontrolling interests									0	0	0
Comprehensive income attributable to common stockholders									(306,068)	(1,265,751)	(626,041)
Ventas, Inc.
Condensed Financial Statements, Captions [Line Items]
Net income									409,467	1,356,470	649,231
Other comprehensive income (loss):
Foreign currency translation									0	0	0
Unrealized gain (loss) on marketable debt securities									0	0
Derivative instruments									0	0	0
Total other comprehensive income (loss)									0	0	0
Comprehensive income									409,467	1,356,470	649,231
Comprehensive income attributable to noncontrolling interests									0	0	0
Comprehensive income attributable to common stockholders									409,467	1,356,470	649,231
Ventas Realty
Condensed Financial Statements, Captions [Line Items]
Net income									(269,557)	508,582	(60,332)
Other comprehensive income (loss):
Foreign currency translation									0	0	0
Unrealized gain (loss) on marketable debt securities									0	0	0
Derivative instruments									0	0	0
Total other comprehensive income (loss)									0	0	0
Comprehensive income									(269,557)	508,582	(60,332)
Comprehensive income attributable to noncontrolling interests									0	0	0
Comprehensive income attributable to common stockholders									(269,557)	508,582	(60,332)
Ventas Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net income									582,139	761,811	688,632
Other comprehensive income (loss):
Foreign currency translation									(9,436)	20,612	(52,266)
Unrealized gain (loss) on marketable debt securities									14,944	(437)	(310)
Derivative instruments									10,030	2,239	2,607
Total other comprehensive income (loss)									15,538	22,414	(49,969)
Comprehensive income									597,677	784,225	638,663
Comprehensive income attributable to noncontrolling interests									6,514	4,642	2,259
Comprehensive income attributable to common stockholders									$ 591,163	$ 779,583	$ 636,404