Sale Of Equipment Installment Receivables (Finance Receivables) (Details) - Finance Receivables [Member] - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||||
|---|---|---|---|---|---|---|
Jun. 30, 2020 |
Jun. 30, 2019 |
Jun. 30, 2020 |
Jun. 30, 2019 |
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| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||||
| Gross receivables sold | $ 1,506 | $ 2,244 | $ 3,873 | $ 4,945 | ||
| Net receivables sold | [1] | 1,449 | 2,133 | 3,722 | 4,679 | |
| Cash proceeds received | 1,225 | 1,920 | 3,175 | 4,195 | ||
| Deferred purchase price recorded | 232 | 261 | 585 | 570 | ||
| Guarantee obligation recorded | $ 27 | $ 93 | $ 71 | $ 194 | ||
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