Recent Transactions (Properties Commencing Initial Operations) (Narrative) (Details) $ in Thousands	9 Months Ended
Sep. 30, 2021 USD ($)
Real Estate Properties [Line Items]
Development costs	$ 262,513
Parsippany, New Jersey [Member]
Real Estate Properties [Line Items]
Development costs	$ 5,100

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration