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Investments (Alternative Investment Portfolio by Strategy and the Remaining Commitment Amount and Maximum Exposure to Loss Associated With Each Strategy) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Carrying Amount	$ (380,028)	$ (371,316)
Private Equity Funds [Member]
Carrying Amount	(289,598)	(280,980)
Remaining Commitment	129,839	134,676
Maximum Exposure to Loss	419,437	415,656
Private Credit Funds [Member]
Carrying Amount	(53,445)	(54,866)
Remaining Commitment	89,002	89,481
Maximum Exposure to Loss	142,447	144,347
Real Assets [Member]
Carrying Amount	(36,985)	(35,470)
Remaining Commitment	20,738	21,945
Maximum Exposure to Loss	57,723	57,415
Alternative Investments [Member]
Carrying Amount	(380,028)	(371,316)
Remaining Commitment	239,579	246,102
Maximum Exposure to Loss	$ 619,607	$ 617,418

X

- Definition

This item represents contractual obligations to invest additional amounts on our other investment portfolio. These additional investments may or may not be required.

+ References

No definition available.

+ Details

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X

- Definition

Fair value of investment other than investment in equity security, investment in debt security and equity method investment. Includes, but is not limited to, investment in certain entities that calculate net asset value per share. Example includes, but is not limited to, investment in hedge fund, venture capital fund, private equity fund, and real estate partnership or fund.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 6A
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=SL6742756-110258

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 35
-Paragraph 54B
-URI https://asc.fasb.org/extlink&oid=126972413&loc=SL7495116-110257

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X

- Definition

The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=123419778&loc=d3e5747-111685

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph b
-URI https://asc.fasb.org/extlink&oid=123419778&loc=d3e5728-111685

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