Investments - Schedule of Unrealized Loss (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value	$ 29,511	$ 6,065
Gross Unrealized Losses	4,056	112
Additional impairment losses	0
AAA
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value	1,559	368
Gross Unrealized Losses	298	6
AA
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value	4,327	875
Gross Unrealized Losses	817	17
A
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value	6,615	1,516
Gross Unrealized Losses	749	23
BBB
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value	13,226	1,812
Gross Unrealized Losses	1,621	42
U.S. Government, Government agencies and Government-sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value	2,355	898
Gross Unrealized Losses	337	8
Non-investment grade
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value	1,429	596
Gross Unrealized Losses	$ 234	$ 16

Amount of additional other-than-temporary impairment losses on investments in available-for-sale securities.

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- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 4
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
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-Section 55
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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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