Investment Activity (Summary of NHC Percentage Rent) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net Investment Income [Line Items]
Rent income from NHC	$ (5,275)	$ (4,662)	$ (5,501)
National HealthCare Corporation
Net Investment Income [Line Items]
Rent income from NHC	(3,126)	(3,531)	(3,673)
Current year \| National HealthCare Corporation
Net Investment Income [Line Items]
Rent income from NHC	(3,332)	(3,536)	(3,687)
Prior year final certification \| National HealthCare Corporation
Net Investment Income [Line Items]
Rent income from NHC	$ (206)	$ (5)	$ (14)

Amount of operating lease income from variable lease payments paid and payable to lessor, excluding amount included in measurement of lease receivable.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 270
-SubTopic 10
-Section 50
-Paragraph 6A
-URI http://asc.fasb.org/extlink&oid=124502072&loc=SL77927221-108306

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=124258985&loc=SL77919372-209981

Name:	us-gaap_OperatingLeaseVariableLeaseIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration