CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Common Stock Par Value	Capital in Excess of Par Value	Accumulated Other Comprehensive Loss	Retained Earnings (Deficit)	Treasury Stock	Total Ventas Stockholders’ Equity	Noncontrolling Interests
Increase (decrease) in stockholders' equity
Cumulative effect change in accounting principles	$ 30,643	$ 0	$ 0	$ 0	$ 30,643	$ 0	$ 30,643	$ 0
Beginning Balance at Dec. 31, 2017	10,932,185	89,029	13,053,057	(35,120)	(2,240,698)	(42)	10,866,226	65,959
Increase (decrease) in stockholders' equity
Net income attributable to common stockholders	347,194	0	0	0	347,194	0	347,194
Net income attributable to noncontrolling interest	5,485							5,485
Net income	352,679
Other comprehensive income	27,173	0	0	27,173	0	0	27,173	0
Net change in noncontrolling interests	(12,640)	0	(1,426)	0	0	0	(1,426)	(11,214)
Dividends to common stockholders	(846,432)	0	0	0	(846,432)	0	(846,432)	0
Issuance of common stock for stock plans	7,443	26	6,179	0	0	1,238	7,443	0
Adjust redeemable OP unitholder interests to current fair value	8,878	0	8,878	0	0	0	8,878	0
Redemption of OP Units	(596)	0	(830)	0	0	234	(596)	0
Grant of restricted stock, net of forfeitures	13,736	45	15,466	0	0	(1,775)	13,736	0
Ending Balance at Sep. 30, 2018	10,513,069	89,100	13,081,324	(7,947)	(2,709,293)	(345)	10,452,839	60,230
Beginning Balance at Jun. 30, 2018	10,677,569	89,085	13,068,399	(10,861)	(2,529,102)	(573)	10,616,948	60,621
Increase (decrease) in stockholders' equity
Net income attributable to common stockholders	101,972	0	0	0	101,972	0	101,972
Net income attributable to noncontrolling interest	1,309							1,309
Net income	103,281
Other comprehensive income	2,914	0	0	2,914	0	0	2,914	0
Net change in noncontrolling interests	(1,661)	0	39	0	0	0	39	(1,700)
Dividends to common stockholders	(282,163)	0	0	0	(282,163)	0	(282,163)	0
Issuance of common stock for stock plans	2,679	10	1,921	0	0	748	2,679	0
Adjust redeemable OP unitholder interests to current fair value	4,592	0	4,592	0	0	0	4,592	0
Redemption of OP Units	(275)	0	(275)	0	0	0	(275)	0
Grant of restricted stock, net of forfeitures	6,133	5	6,648	0	0	(520)	6,133	0
Ending Balance at Sep. 30, 2018	10,513,069	89,100	13,081,324	(7,947)	(2,709,293)	(345)	10,452,839	60,230
Increase (decrease) in stockholders' equity
Cumulative effect change in accounting principles	638	0	0	(163)	801	0	638	0
Beginning Balance at Dec. 31, 2018	10,271,594	89,125	13,076,528	(19,582)	(2,930,214)	0	10,215,857	55,737
Increase (decrease) in stockholders' equity
Net income attributable to common stockholders	421,573	0	0	0	421,573	0	421,573
Net income attributable to noncontrolling interest	4,831							4,831
Net income	426,404
Other comprehensive income	(40,112)	0	0	(40,112)	0	0	(40,112)	0
Net change in noncontrolling interests	108,089	0	(1,546)	0	0	0	(1,546)	109,635
Dividends to common stockholders	(876,581)	0	0	0	(876,581)	0	(876,581)	0
Issuance of common stock	942,436	3,829	938,607	0	0	0	942,436	0
Issuance of common stock for stock plans	61,951	148	57,261	0	0	4,542	61,951	0
Adjust redeemable OP unitholder interests to current fair value	(51,024)	0	(51,024)	0	0	0	(51,024)	0
Redemption of OP Units	(285)	0	(285)	0	0	0	(285)	0
Grant of restricted stock, net of forfeitures	(7,201)	62	(2,511)	0	0	(4,752)	(7,201)	0
Ending Balance at Sep. 30, 2019	10,835,909	93,164	14,017,030	(59,857)	(3,384,421)	(210)	10,665,706	170,203
Beginning Balance at Jun. 30, 2019	10,876,362	92,852	13,940,117	(39,671)	(3,173,287)	0	10,820,011	56,351
Increase (decrease) in stockholders' equity
Net income attributable to common stockholders	85,259	0	0	0	85,259	0	85,259
Net income attributable to noncontrolling interest	1,659							1,659
Net income	86,918
Other comprehensive income	(20,186)	0	0	(20,186)	0	0	(20,186)	0
Net change in noncontrolling interests	112,745	0	552	0	0	0	552	112,193
Dividends to common stockholders	(296,393)	0	0	0	(296,393)	0	(296,393)	0
Issuance of common stock	76,280	276	76,004	0	0	0	76,280	0
Issuance of common stock for stock plans	16,500	35	16,078	0	0	387	16,500	0
Adjust redeemable OP unitholder interests to current fair value	(16,015)	0	(16,015)	0	0	0	(16,015)	0
Redemption of OP Units	(285)	0	(285)	0	0	0	(285)	0
Grant of restricted stock, net of forfeitures	(17)	1	579	0	0	(597)	(17)	0
Ending Balance at Sep. 30, 2019	$ 10,835,909	$ 93,164	$ 14,017,030	$ (59,857)	$ (3,384,421)	$ (210)	$ 10,665,706	$ 170,203