Fixed Maturity Securities In An Unrealized Loss Position (Non-Investment Grade Fixed Maturity Securities) (Details) $ in Thousands	Sep. 30, 2020 USD ($) position	Dec. 31, 2019 USD ($)
Corporate
Debt Securities, Available-for-sale [Line Items]
Aggregate Fair Value	$ 676,474	$ 428,837
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Aggregate Fair Value	145,536	481,506
Asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Aggregate Fair Value	$ 2,108,937	$ 1,529,767
Noninvestment Grade Investments at Loss Position
Debt Securities, Available-for-sale [Line Items]
Number of Securities \| position	43
Aggregate Fair Value	$ 121,888
Gross Unrealized Loss	$ 51,624
Noninvestment Grade Investments at Loss Position \| Foreign government
Debt Securities, Available-for-sale [Line Items]
Number of Securities \| position	22
Aggregate Fair Value	$ 91,413
Gross Unrealized Loss	$ 45,247
Noninvestment Grade Investments at Loss Position \| Corporate
Debt Securities, Available-for-sale [Line Items]
Number of Securities \| position	13
Aggregate Fair Value	$ 28,816
Gross Unrealized Loss	$ 6,343
Noninvestment Grade Investments at Loss Position \| Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Number of Securities \| position	8
Aggregate Fair Value	$ 1,659
Gross Unrealized Loss	$ 34

This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

No definition available.

+ Details

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

- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27290-111563

+ Details

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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

Available For Sale Equity Securities Continuous Unrealized Loss Position Aggregate Loss

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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