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Investments (Other Investment Portfolio by Strategy and the Remaining Commitment Amount Associated With Each Strategy) (Details) - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 31, 2020
Carrying Value		$ 409,032	$ 266,322
Private Equity [Member]
Carrying Value		273,070	157,276
Remaining Commitment		99,734	100,905
Maximum Exposure to Loss	[1]	372,804	258,181
Private Credit Funds [Member]
Carrying Value		63,138	54,017
Remaining Commitment		92,674	98,330
Maximum Exposure to Loss	[1]	155,812	152,347
Real Assets [Member]
Carrying Value		23,524	19,659
Remaining Commitment		22,579	16,493
Maximum Exposure to Loss	[1]	46,103	36,152
Alternative Investments [Member]
Carrying Value		359,732	230,952
Remaining Commitment		214,987	215,728
Maximum Exposure to Loss	[1]	574,719	446,680
Other Securities [Member]
Carrying Value		49,300	35,370
Remaining Commitment		0	0
Maximum Exposure to Loss	[1]	49,300	35,370
Other Investment Portfolio [Member]
Carrying Value		409,032	266,322
Remaining Commitment		214,987	215,728
Maximum Exposure to Loss	[1]	$ 624,019	$ 482,050
[1] In addition to the amounts in this table, previously recognized tax credits are subject to the risk of recapture. We do not consider this significant and therefore do not include in this table.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 210
-Section S99
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