Borrowing Arrangements (Senior Notes) (Details)	12 Months Ended				1 Months Ended				1 Months Ended																12 Months Ended					12 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2012 Senior Notes USD ($)	Jan. 31, 2015 Senior Notes 3.500% Senior Notes due 2025 Subsequent Event USD ($)	Jan. 31, 2015 Senior Notes 4.375% Senior Notes due 2045 Subsequent Event USD ($)	Jan. 31, 2015 Senior Notes 3.30% Series C Senior Notes due 2022 Subsequent Event CAD	Jan. 31, 2015 Senior Notes 3.30% Series C Senior Notes due 2022 Subsequent Event USD ($)	Sep. 30, 2014 Senior Notes 3.00% Senior Notes, Series A due 2019 USD ($)	Sep. 30, 2014 Senior Notes 4.125% Senior Notes, Series B due 2024 USD ($)	Apr. 28, 2014 Senior Notes 1.250% Senior Notes due 2017 USD ($)	Apr. 28, 2014 Senior Notes 3.750% Senior Notes due 2024 USD ($)	Sep. 30, 2013 Senior Notes 1.55% Senior Notes due 2016 USD ($)	Sep. 30, 2013 Senior Notes 5.70% Senior Notes due 2043 USD ($)	Mar. 31, 2013 Senior Notes 5.45% Senior Notes due 2043 USD ($)	Mar. 31, 2013 Senior Notes 2.700% Senior Notes due 2020 USD ($)	Feb. 28, 2013 Senior Notes 6.25% Senior Notes due 2013 USD ($)	Dec. 31, 2012 Senior Notes 2.00% Senior Notes due 2018 USD ($)	Dec. 31, 2012 Senior Notes 3.25% Senior Notes due 2022 USD ($)	Aug. 31, 2012 Senior Notes 3.25% Senior Notes due 2022 USD ($)	Apr. 30, 2012 Senior Notes 4.00% Senior Notes due 2019 USD ($)	Feb. 29, 2012 Senior Notes 4.25% Senior Notes due 2022 USD ($)	Dec. 31, 2012 Senior Notes 9% Senior Notes due 2012	Dec. 31, 2012 Senior Notes 8.25% Senior Notes, Due 2012	Dec. 31, 2012 Senior Notes 6 3/4% Senior Notes due 2017 USD ($)	Dec. 31, 2012 Senior Notes 6 1/2% Senior Notes due 2016 USD ($)	Dec. 31, 2014 Senior Notes 6.90% Senior Notes due 2037	Dec. 31, 2014 Senior Notes 6.59% Senior Notes due 2038	Dec. 31, 2014 NHP Senior Notes USD ($)	Dec. 31, 2014 Ventas Realty USD ($)	Dec. 31, 2013 Ventas Realty USD ($)	Dec. 31, 2012 Ventas Realty USD ($)	Dec. 31, 2014 Ventas Realty Senior Notes USD ($)	Dec. 31, 2014 Ventas Capital Corporation Senior Notes USD ($)	Dec. 31, 2014 Ventas Canada Finance Limited Senior Notes CAD	Jan. 31, 2015 Ventas Canada Finance Limited Senior Notes 3.30% Series C Senior Notes due 2022 Subsequent Event
Debt Instrument [Line Items]
Principal amount outstanding	$ 10,872,371,000	$ 9,320,477,000																											$ 309,800,000				$ 5,800,000,000	$ 4,300,000,000	650,000,000
Debt instrument, face amount					600,000,000.0	300,000,000.0		250,000,000.0	400,000,000	250,000,000	300,000,000	400,000,000	550,000,000	300,000,000	258,800,000	500,000,000		700,000,000	225,000,000	275,000,000	600,000,000	600,000,000
Interest rate (as a percent)					3.50%	4.375%			3.00%	4.125%	1.25%	3.75%	1.55%	5.70%	5.45%	2.70%	6.25%	2.00%		3.25%	4.00%	4.25%	9.00%	8.25%	6.75%	6.50%	6.90%	6.59%								3.30%
Public offering price as percent of par					99.663%	99.50%		99.992%	99.713%	99.601%	99.815%	99.304%	99.91%	99.628%		99.942%		99.739%	98.509%	99.027%	99.489%	99.214%
Proceeds from issuance of debt					598,000,000	298,500,000	250,000,000		398,900,000	249,000,000	299,400,000	397,200,000	549,500,000	298,900,000	258,800,000	499,700,000		698,200,000	221,600,000	272,300,000	596,900,000	595,300,000
Maturities of senior debt				155,400,000													270,000,000
Extinguishment of debt, amount																									225,000,000	200,000,000
Redemption price as a percentage of par																									103.375%	103.25%
Loss on extinguishment of debt	$ (5,564,000)	$ (1,201,000)	$ (37,640,000)	$ 39,700,000																										$ (3,000)	$ (1,510,000)	$ (39,737,000)