Sale of Equipment Installment Receivables (Summary of Receivables Sold) (Details) - WarnerMedia [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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| Transfer Of Financial Assets Accounted For As Sales [Line Items] | ||||||||
| Gross receivables sold/cash proceeds received | [1] | $ 3,805 | $ 4,452 | $ 8,027 | $ 5,852 | |||
| Collections reinvested under revolving agreement | 3,805 | 2,127 | 7,027 | 2,127 | ||||
| Net cash proceeds received (remitted) | 0 | 2,325 | 1,000 | 3,725 | ||||
| Net receivables sold | [2] | 3,819 | 4,134 | 7,957 | 5,497 | |||
| Guarantee obligation recorded | (12) | 384 | 114 | 436 | ||||
| Initial sale of receivables | $ 0 | $ 2,325 | $ 1,000 | $ 3,725 | ||||
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