Accounts Receivable, Net - Summary of Accounts Receivable, Net (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Receivables [Abstract]
Noninsurance customer receivables	$ 6,274
Noninsurance customer receivables		$ 5,534
Pharmaceutical manufacturers receivable	5,463
Pharmaceutical manufacturers receivable		4,676
Insurance customer receivables	2,932
Insurance customer receivables		1,789
Other receivables	456
Other receivables		192
Receivables, Net, Current Before Reclassification To Disposal Group Assets Held For Sale	15,125
Accounts receivable, net classified as Assets of businesses held for sale	(54)
Accounts receivable, net per Consolidated Balance Sheets	$ 15,071	$ 12,191

Accounts And Other Receivables, Net, Current Before Reclassification To Disposal Group Assets Held For Sale

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Receivables due from customers under insurance contracts.

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Insurance Customer Receivables Before Reclassification To Disposal Group Assets Held For Sale

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Receivables due from customers that are not under insurance contracts. These include pharmacy sales and fees due from employer clients.

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Noninsurance Customer Receivables Excluding Pharmaceutical Manufacturers Receivable Before Reclassification To Disposal Group Assets Held For Sale

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Receivables due from pharmaceutical manufacturers related to rebate contracts.

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Pharmaceutical Manufacturers Receivable Before Reclassification To Disposal Group Assets Held For Sale

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Receivables, Net, Current Before Reclassification To Disposal Group Assets Held For Sale

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Amount, after allowance, receivable from customers, clients, or other third-parties, and receivables classified as other due within one year or the normal operating cycle, if longer.

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Amount classified as accounts, notes and loans receivable attributable to disposal group held for sale or disposed of.

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The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value.

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