Short-term and Long-term Investments, Restricted Deposits - By Investment Type (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Debt Securities
Gross Unrealized Gains	$ 252	$ 119
Gross Unrealized Losses	(545)	(860)
Equity securities	15	17
Private equity investments	913	833
Life insurance contracts	196	174
Total, Amortized Cost	22,428	20,872
Total, Fair Value	22,135	20,131
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Debt Securities
Amortized Cost	592	403
Gross Unrealized Gains	6	0
Gross Unrealized Losses	(4)	(8)
Fair Value	594	395
Corporate securities
Debt Securities
Amortized Cost	10,808	9,984
Gross Unrealized Gains	158	78
Gross Unrealized Losses	(277)	(461)
Fair Value	10,689	9,601
Restricted certificates of deposit
Debt Securities
Amortized Cost	3	4
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	3	4
Restricted cash equivalents
Debt Securities
Amortized Cost	73	259
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	73	259
Short-term time deposits
Debt Securities
Amortized Cost	875	746
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	875	746
Municipal securities
Debt Securities
Amortized Cost	4,224	4,135
Gross Unrealized Gains	32	21
Gross Unrealized Losses	(114)	(171)
Fair Value	4,142	3,985
Asset-backed securities
Debt Securities
Amortized Cost	1,773	1,665
Gross Unrealized Gains	22	8
Gross Unrealized Losses	(17)	(35)
Fair Value	1,778	1,638
Residential mortgage-backed securities
Debt Securities
Amortized Cost	1,725	1,503
Gross Unrealized Gains	24	7
Gross Unrealized Losses	(81)	(103)
Fair Value	1,668	1,407
Commercial mortgage-backed securities
Debt Securities
Amortized Cost	1,231	1,149
Gross Unrealized Gains	10	5
Gross Unrealized Losses	(52)	(82)
Fair Value	$ 1,189	$ 1,072

Investments, Debt Securities, Equity Method Investments And Other, Amortized Cost

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Investments, Debt Securities, Equity Securities And Other, Fair Value

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost excluding accrued interest, after allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

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This item represents the amount that could be realized under a life insurance contract or contracts owned by the Entity as of the date of the statement of financial position. Such Entity-owned life insurance policies are commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

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