Sales Of Receivables (Finance Receivables) (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||
| Net receivables sold | $ 15,760 | $ 11,604 | $ 0 |
| Cash proceeds received | 15,888 | 11,989 | 0 |
| Guarantee obligation recorded | 271 | 530 | 0 |
| Equipment Installment | |||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | |||
| Gross receivables sold | 7,270 | 9,921 | 9,391 |
| Net receivables sold | 7,026 | 9,483 | 8,871 |
| Cash proceeds received | 6,089 | 8,189 | 7,488 |
| Deferred purchase price recorded | 1,021 | 1,451 | 1,578 |
| Guarantee obligation recorded | $ 157 | $ 341 | $ 361 |