| Summary of Significant Accounting Policies - Receivables and Investments (Details) - USD ($) $ in Millions | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | |
| Summary of Significant Accounting Policies | 听 | 听 | 听 | 
| Balance, beginning of period | $ 14 | $ 13 | $ 17 | 
| Provision for Doubtful Accounts | 59 | 59 | 54 | 
| Write-offs | (56) | (59) | (58) | 
| Foreign currency translation adjustments | 听 | 1 | 听 | 
| Balance, end of period | 17 | 14 | $ 13 | 
| Debt and equity securities | $ 113 | $ 80 | 听 | 
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- References No definition available. 
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- Definition Amount of allowance for credit loss on accounts receivable, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of direct write-downs of accounts receivable charged against the allowance. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of foreign currency translation gain (loss) which decreases (increases) allowance for credit loss on financing receivable. Excludes net investment in lease. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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- Definition Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of expense (reversal of expense) for expected credit loss on accounts receivable. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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