Carrying Value of Outstanding Debt (Detail) - USD ($) | 9 Months Ended | | |
Sep. 30, 2018 | Jan. 15, 2018 | Dec. 31, 2017 |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 24,230,000,000 | | |
Debt instrument, stated interest rate | 8.375% | | |
Total debt | $ 23,301,000,000 | | $ 24,289,000,000 |
Less current maturities | (3,200,000,000) | | (4,011,000,000) |
Long-Term Debt | 20,101,000,000 | | 20,278,000,000 |
Commercial Paper | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 2,815,000,000 | | |
Maturity - Minimum Date | Mar. 31, 2017 | | |
Maturity - Maximum Date | Dec. 31, 2018 | | |
Total debt | $ 2,815,000,000 | | 3,203,000,000 |
Senior notes | 5.50% stated rate | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 750,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2018 | | |
Debt instrument, stated interest rate | 5.50% | 5.50% | |
Total debt | $ 0 | | 751,000,000 |
Senior notes | 5.125% stated rate | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 1,000,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2019 | | |
Debt instrument, stated interest rate | 5.125% | | |
Total debt | $ 1,004,000,000 | | 1,019,000,000 |
Senior notes | 3.125% stated rate | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 1,500,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2021 | | |
Debt instrument, stated interest rate | 3.125% | | |
Total debt | $ 1,509,000,000 | | 1,549,000,000 |
Senior notes | 2.050% senior notes [Member] | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 700,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2021 | | |
Debt instrument, stated interest rate | 2.05% | | |
Total debt | $ 697,000,000 | | 696,000,000 |
Senior notes | 2.400% senior note | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 500,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2026 | | |
Debt instrument, stated interest rate | 2.40% | | |
Total debt | $ 497,000,000 | | 497,000,000 |
Senior notes | 3.050% senior notes [Member] | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 1,000,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2027 | | |
Debt instrument, stated interest rate | 3.05% | | |
Total debt | $ 991,000,000 | | 990,000,000 |
Senior notes | 2.45% senior notes | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 1,000,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2022 | | |
Debt instrument, stated interest rate | 2.45% | | |
Total debt | $ 952,000,000 | | 979,000,000 |
Senior notes | 2.350% senior notes | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 600,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2022 | | |
Debt instrument, stated interest rate | 2.35% | | |
Total debt | $ 597,000,000 | | 597,000,000 |
Senior notes | 2.500% senior notes [Member] | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 1,000,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2023 | | |
Debt instrument, stated interest rate | 2.50% | | |
Total debt | $ 994,000,000 | | 992,000,000 |
Senior notes | 2.800% senior notes [Member] | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 500,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2024 | | |
Debt instrument, stated interest rate | 2.80% | | |
Total debt | $ 496,000,000 | | 495,000,000 |
Senior notes | 6.20% stated rate | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 1,500,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2038 | | |
Debt instrument, stated interest rate | 6.20% | | |
Total debt | $ 1,482,000,000 | | 1,482,000,000 |
Senior notes | 4.875% stated rate | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 500,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2040 | | |
Debt instrument, stated interest rate | 4.875% | | |
Total debt | $ 490,000,000 | | 489,000,000 |
Senior notes | 3.625% senior notes | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 375,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2042 | | |
Debt instrument, stated interest rate | 3.625% | | |
Total debt | $ 368,000,000 | | 368,000,000 |
Senior notes | 3.400% senior notes | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 500,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2046 | | |
Debt instrument, stated interest rate | 3.40% | | |
Total debt | $ 491,000,000 | | 491,000,000 |
Senior notes | 3.750% senior notes [Member] | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 1,150,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2047 | | |
Debt instrument, stated interest rate | 3.75% | | |
Total debt | $ 1,136,000,000 | | 1,135,000,000 |
Senior notes | Floating Rate Senior Notes 2 [Member] | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 350,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2021 | | |
Total debt | $ 348,000,000 | | 348,000,000 |
Senior notes | 8.375% debentures | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 424,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2029 | | |
Debt instrument, stated interest rate | 8.375% | | |
Total debt | $ 434,000,000 | | 447,000,000 |
Senior notes | 8.375% debentures | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 276,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2030 | | |
Total debt | $ 281,000,000 | | 282,000,000 |
Senior notes | Canadian senior note 2.125% | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 575,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2024 | | |
Debt instrument, stated interest rate | 2.125% | | |
Total debt | $ 572,000,000 | | 593,000,000 |
Senior notes | Floating rate senior notes | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 400,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2022 | | |
Total debt | $ 399,000,000 | | 398,000,000 |
Senior notes | Floating Rate Senior Notes 3 [Member] | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 500,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2023 | | |
Total debt | $ 499,000,000 | | 496,000,000 |
Senior notes | Floating Rate Senior Notes 4 [Member] | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 1,043,000,000 | | |
Maturity - Minimum Date | Dec. 31, 2049 | | |
Maturity - Maximum Date | Dec. 31, 2067 | | |
Total debt | $ 1,030,000,000 | | 1,032,000,000 |
Capital Lease Obligations | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 900,000,000 | | |
Maturity - Minimum Date | Dec. 31, 2018 | | |
Maturity - Maximum Date | Dec. 31, 3005 | | |
Total debt | $ 900,000,000 | | 500,000,000 |
Pound Sterling notes | 5.500% notes | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 87,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2031 | | |
Debt instrument, stated interest rate | 5.50% | | |
Total debt | $ 86,000,000 | | 84,000,000 |
Pound Sterling notes | 5.125% notes | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 593,000,000 | | |
Maturity - Maximum Date | Jan. 1, 2022 | | |
Debt instrument, stated interest rate | 5.125% | | |
Total debt | $ 561,000,000 | | 586,000,000 |
Euro Senior Notes | 0.375% Euro Senior Notes [Member] | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 811,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2023 | | |
Debt instrument, stated interest rate | 0.375% | | |
Total debt | $ 805,000,000 | | 832,000,000 |
Euro Senior Notes | 1.625% Euro Senior Notes | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 811,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2025 | | |
Debt instrument, stated interest rate | 1.625% | | |
Total debt | $ 806,000,000 | | 833,000,000 |
Euro Senior Notes | 1.000% notes | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 579,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2028 | | |
Debt instrument, stated interest rate | 1.00% | | |
Total debt | $ 575,000,000 | | 595,000,000 |
Euro Senior Notes | 1.500% Euro Senior Notes [Member] | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 579,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2032 | | |
Debt instrument, stated interest rate | 1.50% | | |
Total debt | $ 575,000,000 | | 594,000,000 |
Euro Senior Notes | Floating-rate senior notes | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 579,000,000 | | |
Maturity - Maximum Date | Dec. 31, 2020 | | |
Total debt | $ 578,000,000 | | 598,000,000 |
Facility notes and bonds | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 320,000,000 | | |
Maturity - Minimum Date | Dec. 31, 2029 | | |
Maturity - Maximum Date | Dec. 31, 2045 | | |
Total debt | $ 320,000,000 | | 319,000,000 |
Other debt | | | |
Debt Instrument [Line Items] | | | |
Debt Instrument, Face Amount | $ 13,000,000 | | |
Maturity - Minimum Date | Dec. 31, 2018 | | |
Maturity - Maximum Date | Dec. 31, 2022 | | |
Total debt | $ 13,000,000 | | $ 19,000,000 |