Summary of Significant Accounting Policies (Details) $ in Thousands		3 Months Ended	12 Months Ended
	Jan. 01, 2018 USD ($)	Mar. 31, 2019 facility	Dec. 31, 2019 USD ($) facility	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)		Dec. 31, 2017 USD ($)	[2]	Jan. 31, 2017 USD ($)
Accounting Policies [Abstract]
Residency agreement term, minimum			30 days
Residency agreement term, maximum			1 year
Maximum period available for occupancy from cessation of significant construction activity			1 year
Maximum useful life of building and improvements			60 years
Schedule of Equity Method Investments [Line Items]
HCP’s capital			$ 6,085,058		$ 5,944,439
Cumulative effect of new accounting principle					590	[1]	$ 79,144
Present value of lease liability			156,611
Right-of-use asset, net			172,486
Intangible assets, net			$ 331,693		305,079
RIDEA II
Schedule of Equity Method Investments [Line Items]
Investment ownership percentage									40.00%
Equity method investments									$ 121,000
ASU 2016-02
Schedule of Equity Method Investments [Line Items]
Present value of lease liability				$ 153,000
Right-of-use asset, net				166,000
Accrued Rent				20,000
Intangible assets, net				33,000
Difference between Revenue Guidance in Effect before and after Topic 606 | ASU 2014-09
Schedule of Equity Method Investments [Line Items]
HCP’s capital	$ 79,000
Cumulative effect of change on beginning retained earnings	30,000
Difference between Revenue Guidance in Effect before and after Topic 606 | ASU 2014-09 | RIDEA II
Schedule of Equity Method Investments [Line Items]
Fair value of equity investment	$ 107,000
Cumulative Dividends In Excess Of Earnings
Schedule of Equity Method Investments [Line Items]
Cumulative effect of new accounting principle					$ 590	[1]	$ 79,144
Cumulative Dividends In Excess Of Earnings | ASU 2016-02
Schedule of Equity Method Investments [Line Items]
Cumulative effect of new accounting principle				$ 1,000
Medical office
Schedule of Equity Method Investments [Line Items]
Number of SH NNN facilities transitioned to RIDEA structure (in facilities) | facility		2	2

[1] On January 1, 2019, the Company adopted a series of ASUs related to accounting for leases, and recognized the cumulative-effect of adoption to beginning retained earnings. Refer to Note 2 for a detailed impact of adoption.

[2] On January 1, 2018, the Company adopted Accounting Standards Update (“ASU”) No. 2017-05, Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets (“ASU 2017-05”), and recognized the cumulative-effect of adoption to beginning retained earnings. Refer to Note 2 for a detailed impact of adoption.