Segment Information (Narrative) (Details) - country	Dec. 31, 2019	Oct. 15, 2018
PSB [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest, percentage	42.00%
Shurgard [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest, percentage	35.00%	35.00%
Number of countries in which entity operates	7

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant