Borrowing Arrangements (Senior Notes) (Details)	1 Months Ended									12 Months Ended
	Sep. 30, 2015 USD ($)	Jul. 31, 2015 USD ($)	Jan. 31, 2015 CAD	Jan. 31, 2015 USD ($)	Sep. 30, 2014 CAD	Apr. 30, 2014 USD ($)	Sep. 30, 2013 USD ($)	Mar. 31, 2013 USD ($)	Feb. 28, 2013 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2015 CAD	Dec. 31, 2015 USD ($)	May. 31, 2015 USD ($)	Jan. 31, 2015 USD ($)	Dec. 31, 2012
Debt Instrument [Line Items]
Principal amount outstanding											$ 10,888,295,000			$ 11,271,020,000
Gain (loss) on extinguishment of debt										$ (14,411,000)	(5,564,000)	$ (1,201,000)
Senior Notes | 3.125% Senior Notes due 2015
Debt Instrument [Line Items]
Interest rate (as a percent)	3.125%
Debt instrument, redemption price, percentage	100.70%
Extinguishment of debt, amount	$ 400,000,000
Gain (loss) on extinguishment of debt	$ (2,900,000)
Senior Notes | 4.125% Senior Notes due 2026
Debt Instrument [Line Items]
Interest rate (as a percent)		4.125%
Debt instrument, face amount		$ 500,000,000.0
Public offering price as percent of par		99.218%
Proceeds from issuance of debt		$ 496,100,000
Senior Notes | 6% Senior Notes due 2015
Debt Instrument [Line Items]
Interest rate (as a percent)															6.00%
Debt instrument, face amount															$ 234,400,000.0
Senior Notes | 3.500% Senior Notes due 2025
Debt Instrument [Line Items]
Interest rate (as a percent)			3.50%													3.50%
Debt instrument, face amount																$ 600,000,000.0
Public offering price as percent of par			99.663%													99.663%
Proceeds from issuance of debt				$ 598,000,000
Senior Notes | 4.375% Senior Notes due 2045
Debt Instrument [Line Items]
Interest rate (as a percent)			4.375%													4.375%
Debt instrument, face amount																$ 300,000,000.0
Public offering price as percent of par			99.50%													99.50%
Proceeds from issuance of debt				$ 298,500,000
Senior Notes | 1.250% Senior Notes due 2017
Debt Instrument [Line Items]
Interest rate (as a percent)						1.25%
Debt instrument, face amount						$ 300,000,000.0
Public offering price as percent of par						99.815%
Proceeds from issuance of debt						$ 299,400,000
Senior Notes | 3.750% Senior Notes due 2024
Debt Instrument [Line Items]
Interest rate (as a percent)						3.75%
Debt instrument, face amount						$ 400,000,000.0
Public offering price as percent of par						99.304%
Proceeds from issuance of debt						$ 397,200,000
Senior Notes | 1.55% Senior Notes due 2016
Debt Instrument [Line Items]
Interest rate (as a percent)							1.55%
Debt instrument, face amount							$ 550,000,000.0
Public offering price as percent of par							99.91%
Proceeds from issuance of debt							$ 549,500,000
Senior Notes | 5.70% Senior Notes due 2043
Debt Instrument [Line Items]
Interest rate (as a percent)							5.70%
Debt instrument, face amount							$ 300,000,000.0
Public offering price as percent of par							99.628%
Proceeds from issuance of debt							$ 298,900,000
Senior Notes | 5.45% Senior Notes due 2043
Debt Instrument [Line Items]
Interest rate (as a percent)								5.45%
Debt instrument, face amount								$ 258,800,000
Proceeds from issuance of debt								$ 258,800,000
Senior Notes | 2.700% Senior Notes due 2020
Debt Instrument [Line Items]
Interest rate (as a percent)								2.70%
Debt instrument, face amount								$ 500,000,000.0
Public offering price as percent of par								99.942%
Proceeds from issuance of debt								$ 499,700,000
Senior Notes | 6.25% Senior Notes due 2013
Debt Instrument [Line Items]
Interest rate (as a percent)									6.25%
Maturities of senior debt									$ 270,000,000
Senior Notes | 6 3/4% Senior Notes due 2017
Debt Instrument [Line Items]
Interest rate (as a percent)																	6.75%
Senior Notes | 6 1/2% Senior Notes due 2016
Debt Instrument [Line Items]
Interest rate (as a percent)																	6.50%
Senior Notes | 6.90% Senior Notes due 2037
Debt Instrument [Line Items]
Interest rate (as a percent)													6.90%	6.90%
Senior Notes | 6.59% Senior Notes due 2038
Debt Instrument [Line Items]
Interest rate (as a percent)													6.59%	6.59%
Nhp | Senior Notes
Debt Instrument [Line Items]
Principal amount outstanding														$ 75,400,000
Ventas Realty
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt										$ (4,523,000)	$ (3,000)	$ (1,510,000)
Ventas Realty | Senior Notes
Debt Instrument [Line Items]
Principal amount outstanding														6,800,000,000
Ventas Capital Corporation | Senior Notes
Debt Instrument [Line Items]
Principal amount outstanding														$ 3,900,000,000
Ventas Canada Finance Limited | Senior Notes
Debt Instrument [Line Items]
Principal amount outstanding | CAD													CAD 900,000,000
Ventas Canada Finance Limited | Senior Notes | Ventas Canada Finance Limited Series C Senior Notes due 2022
Debt Instrument [Line Items]
Interest rate (as a percent)			3.30%													3.30%
Debt instrument, face amount | CAD			CAD 250,000,000
Public offering price as percent of par			99.992%													99.992%
Proceeds from issuance of debt | CAD			CAD 250,000,000
Ventas Canada Finance Limited | Senior Notes | Ventas Canada Finance Limited Series A Senior Notes Due 2019
Debt Instrument [Line Items]
Interest rate (as a percent)					3.00%
Debt instrument, face amount | CAD					CAD 400,000,000.0
Public offering price as percent of par					99.713%
Proceeds from issuance of debt | CAD					CAD 398,900,000
Ventas Canada Finance Limited | Senior Notes | Ventas Canada Finance Limited Series B Senior Notes Due 2024
Debt Instrument [Line Items]
Interest rate (as a percent)					4.125%
Debt instrument, face amount | CAD					CAD 250,000,000.0
Public offering price as percent of par					99.601%
Proceeds from issuance of debt | CAD					CAD 249,000,000