Mortgage Loans Mortgage Loans - Schedule of Troubled Debt Restructuring Mortgage Loan Information (Details) $ in Thousands	6 Months Ended
Jun. 30, 2019 USD ($) loan	Jun. 30, 2018 USD ($) loan
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	7	0
Recorded Investment Pre-Modification	$ 70,175	$ 0
Recorded Investment Post Modification	$ 70,175	$ 0
Office
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	1	0
Recorded Investment Pre-Modification	$ 9,331	$ 0
Recorded Investment Post Modification	$ 9,331	$ 0
Retail
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	2	0
Recorded Investment Pre-Modification	$ 40,249	$ 0
Recorded Investment Post Modification	$ 40,249	$ 0
Industrial
Financing Receivable, Modifications [Line Items]
Number of Loans \| loan	4	0
Recorded Investment Pre-Modification	$ 20,595	$ 0
Recorded Investment Post Modification	$ 20,595	$ 0

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No definition available.

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

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- Definition

Amount, after troubled debt restructuring, of modified financing receivable.

+ References

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- Definition

Amount, before troubled debt restructuring, of financing receivable to be modified.

+ References

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