Real Estate Activities - Loans - Additional Information (Detail) $ in Thousands	Dec. 31, 2018 USD ($) Property Operator
Primotop Holdings S.a.r.l. [Member]
Business Acquisition [Line Items]
Shareholder loan to joint venture \| $	$ 290
Mortgage Loans [Member] \| Steward [Member]
Business Acquisition [Line Items]
Number of Real Estate Properties \| Property	10
Number Of Operators \| Operator	4

For an unclassified balance sheet, amounts due from an entity in which the reporting entity shares joint control with another party or group.

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Name:	us-gaap_DueFromJointVentures
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant