Investment and Disposition Activity - Disposition Narrative (Details) - Dispositions Second Quarter 2019 - Disposal Group, Disposed of by Sale, Not Discontinued Operations $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019 USD ($) buildings	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) buildings	Sep. 30, 2018 USD ($)
Business Acquisition [Line Items]
Number of medical office buildings \| buildings	3		3
Proceeds from divestiture of businesses			$ 15,300
Gain (loss) on sale of investment properties	$ 409	$ 0	$ 3,442	$ 0

Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2443-110228

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230

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