Medical Claims and Benefits Payable - Medical Claims and Benefits Payable (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2021
Other Liabilities Disclosure [Abstract]
Claims incurred but not paid (“IBNP”)	$ 2,915	$ 2,597
Pharmacy payable	197	206
Capitation payable	92	94
Other	1,031	631
Total	$ 4,235	$ 3,528	$ 3,622	$ 3,363

The amount needed to reflect the estimated ultimate cost of settling claims relating to insured events that have occurred on or before the balance sheet date, whether or not reported to the insurer at that date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (cc)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480081/944-40-50-3

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480081/944-40-50-3

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