Investments - Investments - Mortgage Loans- Valuation Allowance Activity (Details) $ in Millions	3 Months Ended
Mar. 31, 2021 USD ($)	Mar. 31, 2020	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans held-for-sale	0		0
Number of loans with modifications	0	0
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 0

Number of loans held-for-sale

No definition available.

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- Definition

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.

+ References

No definition available.

+ Details

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- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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=121611835&loc=SL6953676-111524

+ Details

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- Details

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Balance Type:
Period Type: