Significant Accounting Policies - Receivables (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 2,460	$ 2,302
Government receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,737	1,702
Pharmacy rebate receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	316	291
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 407	$ 309

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.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481372/852-10-55-10

Name:	us-gaap_ReceivablesNetCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant