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Loans Payable, Long-Term Debt and Leases - Long-Term Debt (Details) - USD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Debt Instrument [Line Items] |  |
Long-Term Debt | $ 25,360 | $ 22,736
2.75% notes due 2025 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 2.75% |
Long-Term Debt | $ 2,493 | 2,492
3.70% notes due 2045 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 3.70% |
Long-Term Debt | $ 1,976 | 1,975
2.80% notes due 2023 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 2.80% |
Long-Term Debt | $ 1,748 | 1,747
3.40% notes due 2029 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 3.40% |
Long-Term Debt | $ 1,734 | 1,732
4.00% notes due 2049 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 4.00% |
Long-Term Debt | $ 1,469 | 1,468
2.35% notes due 2040 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 2.35% |
Long-Term Debt | $ 982 | 0
4.15% notes due 2043 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 4.15% |
Long-Term Debt | $ 1,238 | 1,238
1.45% notes due 2030 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 1.45% |
Long-Term Debt | $ 1,233 | 0
1.875% euro-denominated notes due 2026 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 1.875% |
Long-Term Debt | $ 1,218 | 1,107
2.45% notes due 2050 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 2.45% |
Long-Term Debt | $ 1,211 | 0
2.40% notes due 2022 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 2.40% |
Long-Term Debt | $ 1,032 | 1,010
0.75% notes due 2026 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 0.75% |
Long-Term Debt | $ 991 | 0
3.90% notes due 2039 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 3.90% |
Long-Term Debt | $ 983 | 982
2.35% notes due 2022 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 2.35% |
Long-Term Debt | $ 1,269 | 1,248
2.90% notes due 2024 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 2.90% |
Long-Term Debt | $ 746 | 745
6.50% notes due 2033 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 6.50% |
Long-Term Debt | $ 719 | 722
0.50% euro-denominated notes due 2024 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 0.50% |
Long-Term Debt | $ 611 | 555
1.375% euro-denominated notes due 2036 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 1.375% |
Long-Term Debt | $ 606 | 551
2.50% euro-denominated notes due 2034 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 2.50% |
Long-Term Debt | $ 605 | 550
3.60% notes due 2042 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 3.60% |
Long-Term Debt | $ 491 | 490
6.55% notes due 2037 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 6.55% |
Long-Term Debt | $ 411 | 412
5.75% notes due 2036 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 5.75% |
Long-Term Debt | $ 338 | 338
5.95% debentures due 2028 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 5.95% |
Long-Term Debt | $ 306 | 306
5.85% notes due 2039 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 5.85% |
Long-Term Debt | $ 271 | 271
6.40% debentures due 2028 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 6.40% |
Long-Term Debt | $ 250 | 250
6.30% debentures due 2026 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 6.30% |
Long-Term Debt | $ 135 | 135
3.875% notes due 2021 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 3.875% |
Long-Term Debt | $ 0 | 1,151
1.125% euro-denominated notes due 2021 |  |
Debt Instrument [Line Items] |  |
Stated interest rate (as percent) | 1.125% |
Long-Term Debt | $ 0 | 1,113
Other |  |
Debt Instrument [Line Items] |  |
Long-Term Debt | $ 294 | $ 148

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