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	249,398	0	0	0	245,222	0	245,222	4,176
Other comprehensive income	24,259	0	0	24,259	0	0	24,259	0
Net change in noncontrolling interests	(10,979)	0	(1,465)	0	0	0	(1,465)	(9,514)
Dividends to common stockholders	(564,269)	0	0	0	(564,269)	0	(564,269)	0
Issuance of common stock for stock plans	4,764	16	4,258	0	0	490	4,764	0
Adjust redeemable OP unitholder interests to current fair value	4,286	0	4,286	0	0	0	4,286	0
Redemption of OP Units	(321)	0	(555)	0	0	234	(321)	0
Grant of restricted stock, net of forfeitures	7,603	40	8,818	0	0	(1,255)	7,603	0
Ending Balance at Jun. 30, 2018	10,677,569	89,085	13,068,399	(10,861)	(2,529,102)	(573)	10,616,948	60,621
Beginning Balance at Mar. 31, 2018	10,804,044	89,062	13,080,220	(14,474)	(2,413,440)	(553)	10,740,815	63,229
Increase (decrease) in stockholders' equity
Net income	169,300	0	0	0	166,519	0	166,519	2,781
Other comprehensive income	3,613	0	0	3,613	0	0	3,613	0
Net change in noncontrolling interests	(7,624)	0	(2,235)	0	0	0	(2,235)	(5,389)
Dividends to common stockholders	(282,181)	0	0	0	(282,181)	0	(282,181)	0
Issuance of common stock for stock plans	3,603	15	3,098	0	0	490	3,603	0
Adjust redeemable OP unitholder interests to current fair value	(19,251)	0	(19,251)	0	0	0	(19,251)	0
Redemption of OP Units	(194)	0	(194)	0	0	0	(194)	0
Grant of restricted stock, net of forfeitures	6,259	8	6,761	0	0	(510)	6,259	0
Ending 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
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	339,486	0	0	0	336,314	0	336,314	3,172
Other comprehensive income	(19,926)	0	0	(19,926)	0	0	(19,926)	0
Net change in noncontrolling interests	(4,656)	0	(2,098)	0	0	0	(2,098)	(2,558)
Dividends to common stockholders	(580,188)	0	0	0	(580,188)	0	(580,188)	0
Issuance of common stock	866,156	3,553	862,603	0	0	0	866,156	0
Issuance of common stock for stock plans	45,451	113	41,183	0	0	4,155	45,451	0
Adjust redeemable OP unitholder interests to current fair value	(35,009)	0	(35,009)	0	0	0	(35,009)	0
Grant of restricted stock, net of forfeitures	(7,184)	61	(3,090)	0	0	(4,155)	(7,184)	0
Ending Balance at Jun. 30, 2019	10,876,362	92,852	13,940,117	(39,671)	(3,173,287)	0	10,820,011	56,351
Beginning Balance at Mar. 31, 2019	10,206,013	89,579	13,160,550	(12,065)	(3,088,401)	0	10,149,663	56,350
Increase (decrease) in stockholders' equity
Net income	211,898	0	0	0	210,529	0	210,529	1,369
Other comprehensive income	(27,606)	0	0	(27,606)	0	0	(27,606)	0
Net change in noncontrolling interests	(1,776)	0	(408)	0	0	0	(408)	(1,368)
Dividends to common stockholders	(295,415)	0	0	0	(295,415)	0	(295,415)	0
Issuance of common stock	767,718	3,163	764,555	0	0	0	767,718	0
Issuance of common stock for stock plans	31,533	104	31,364	0	0	65	31,533	0
Adjust redeemable OP unitholder interests to current fair value	(15,941)	0	(15,941)	0	0	0	(15,941)	0
Grant of restricted stock, net of forfeitures	(62)	6	(3)	0	0	(65)	(62)	0
Ending Balance at Jun. 30, 2019	$ 10,876,362	$ 92,852	$ 13,940,117	$ (39,671)	$ (3,173,287)	$ 0	$ 10,820,011	$ 56,351