The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82921503&loc=d3e21338-158488

Name:	us-gaap_AllowanceForLoanAndLeaseLossesRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Real Estate Loans Receivable (Textuals) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2018	Jun. 30, 2017
Financing Receivable, Modifications [Line Items]
Allowance for loan losses	$ 68,372		$ 68,372	$ 5,811
Genesis Healthcare Loans [Member] \| Triple Net
Financing Receivable, Modifications [Line Items]
Provision For Loan And Lease Losses Real Estate Excluding Write Off	$ 62,966	$ 6,935