v3.20.4

Share-Based Payments (Narrative) (Details) - USD ($) shares in Millions, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Number of authorized shares of common stock for share-based payment arrangements (in shares) | 183 |  |
Total unrecognized compensation cost related to nonvested share-based payment arrangements granted | $ 709 |  |
Weighted-average period to recognize the cost (years) - nonvested units | 2 years 1 month 2 days |  |
Total fair value of shares vested during the year - nonvested units | $ 647 | $ 798 | $ 766
Cash proceeds from exercise of stock options | $ 65 | $ 446 | $ 361
Restricted stock and stock units | Minimum |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 4 years |  |
Restricted stock and stock units | Maximum |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 5 years |  |
Restricted stock and stock units | Time Warner | Minimum |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 1 year |  |
Restricted stock and stock units | Time Warner | Maximum |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 4 years |  |
Stock options | Time Warner |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 1 year |  |
Performance stock units |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 3 years |  |
Other nonvested stock units |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Vesting period | 3 years |  |

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- Definition Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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