Long-Term Debt (Detail) - USD ($) $ in Millions | Sep. 30, 2016 | Jun. 30, 2016 | Dec. 31, 2015 |
Debt Instrument [Line Items] | | | |
Credit Facility | $ 989 | | $ 0 |
Other | 105 | | 113 |
Capital lease obligations | 167 | | 0 |
Total debt | 8,822 | | 4,107 |
Less: Current portion of long-term debt | (316) | | (300) |
Long-term debt, noncurrent | 8,506 | | 3,807 |
Series H Notes, interest rate of 6.2%, face amount of $289, matured June 15, 2016 (effective interest rate of 6.3%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 0 | | 289 |
Series I Notes, interest rate of 6.4%, face amount of $293, maturing June 15, 2017 (effective interest rate of 6.5%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 293 | | 293 |
Series K Notes, interest rate of 3.0%, face amount of $600, maturing March 1, 2019 (effective interest rate of 4.4%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 596 | | 595 |
Series L Notes, interest rate of 3.3%, face amount of $350, maturing September 15, 2022 (effective interest rate of 3.4%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 348 | | 348 |
Series M Notes, interest rate of 3.4%, face amount of $350, maturing October 15, 2020 (effective interest rate of 3.6%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 347 | | 347 |
Series N Notes, interest rate of 3.1%, face amount of $400, maturing October 15, 2021 (effective interest rate of 3.4%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 396 | | 395 |
Series O Notes, interest rate of 2.9%, face amount of $450, maturing March 1, 2021 (effective interest rate of 3.1%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 446 | | 446 |
Series P Notes, interest rate of 3.8%, face amount of $350, maturing October 1, 2025 (effective interest rate of 4.0%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 344 | | 343 |
Series Q Notes, interest rate of 2.3%, face amount of $750, maturing January 15, 2022 (effective interest rate of 2.5%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 742 | | 0 |
Series R Notes, interest rate of 3.1%, face amount of $750, maturing June 15, 2026 (effective interest rate of 3.3%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 742 | | 0 |
2018 Senior Notes, interest rate of 6.8%, face amount $371, maturing May 15, 2018 (effective interest rate of 1.6%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 403 | | 0 |
2019 Senior Notes, interest rate of 7.2%, face amount $210, maturing December 1, 2019 (effective interest rate of 2.2%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 245 | | 0 |
2023 Senior Notes, interest rate of 3.1%, face amount $350, maturing February 15, 2023 (effective interest rate of 3.1%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 350 | | 0 |
2025 Senior Notes, interest rate of 3.8%, face amount $350, maturing March 15, 2025 (effective interest rate of 2.8%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | 375 | | 0 |
2034 Senior Notes, interest rate of 4.5%, face amount $300, maturing October 1, 2034 (effective interest rate of 4.1%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes | $ 317 | | $ 0 |
Senior Notes | Series H Notes, interest rate of 6.2%, face amount of $289, matured June 15, 2016 (effective interest rate of 6.3%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | | | 6.20% |
Senior notes, face amount | | | $ 289 |
Senior notes, effective interest rate | | | 6.30% |
Senior Notes | Series I Notes, interest rate of 6.4%, face amount of $293, maturing June 15, 2017 (effective interest rate of 6.5%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 6.40% | | 6.40% |
Senior notes, face amount | $ 293 | | $ 293 |
Senior notes, effective interest rate | 6.50% | | 6.50% |
Senior Notes | Series K Notes, interest rate of 3.0%, face amount of $600, maturing March 1, 2019 (effective interest rate of 4.4%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 3.00% | | 3.00% |
Senior notes, face amount | $ 600 | | $ 600 |
Senior notes, effective interest rate | 4.40% | | 4.40% |
Senior Notes | Series L Notes, interest rate of 3.3%, face amount of $350, maturing September 15, 2022 (effective interest rate of 3.4%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 3.30% | | 3.30% |
Senior notes, face amount | $ 350 | | $ 350 |
Senior notes, effective interest rate | 3.40% | | 3.40% |
Senior Notes | Series M Notes, interest rate of 3.4%, face amount of $350, maturing October 15, 2020 (effective interest rate of 3.6%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 3.40% | | 3.40% |
Senior notes, face amount | $ 350 | | $ 350 |
Senior notes, effective interest rate | 3.60% | | 3.60% |
Senior Notes | Series N Notes, interest rate of 3.1%, face amount of $400, maturing October 15, 2021 (effective interest rate of 3.4%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 3.10% | | 3.10% |
Senior notes, face amount | $ 400 | | $ 400 |
Senior notes, effective interest rate | 3.40% | | 3.40% |
Senior Notes | Series O Notes, interest rate of 2.9%, face amount of $450, maturing March 1, 2021 (effective interest rate of 3.1%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 2.90% | | 2.90% |
Senior notes, face amount | $ 450 | | $ 450 |
Senior notes, effective interest rate | 3.10% | | 3.10% |
Senior Notes | Series P Notes, interest rate of 3.8%, face amount of $350, maturing October 1, 2025 (effective interest rate of 4.0%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 3.80% | | 3.80% |
Senior notes, face amount | $ 350 | | $ 350 |
Senior notes, effective interest rate | 4.00% | | 4.00% |
Senior Notes | Series Q Notes, interest rate of 2.3%, face amount of $750, maturing January 15, 2022 (effective interest rate of 2.5%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 2.30% | 2.30% | |
Senior notes, face amount | $ 750 | | |
Senior notes, effective interest rate | 2.50% | | |
Senior Notes | Series R Notes, interest rate of 3.1%, face amount of $750, maturing June 15, 2026 (effective interest rate of 3.3%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 3.10% | 3.125% | |
Senior notes, face amount | $ 750 | | |
Senior notes, effective interest rate | 3.30% | | |
Senior Notes | 2018 Senior Notes, interest rate of 6.8%, face amount $371, maturing May 15, 2018 (effective interest rate of 1.6%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 6.80% | | |
Senior notes, face amount | $ 371 | | |
Senior notes, effective interest rate | 1.60% | | |
Senior Notes | 2019 Senior Notes, interest rate of 7.2%, face amount $210, maturing December 1, 2019 (effective interest rate of 2.2%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 7.20% | | |
Senior notes, face amount | $ 210 | | |
Senior notes, effective interest rate | 2.20% | | |
Senior Notes | 2023 Senior Notes, interest rate of 3.1%, face amount $350, maturing February 15, 2023 (effective interest rate of 3.1%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 3.10% | | |
Senior notes, face amount | $ 350 | | |
Senior notes, effective interest rate | 3.10% | | |
Senior Notes | 2025 Senior Notes, interest rate of 3.8%, face amount $350, maturing March 15, 2025 (effective interest rate of 2.8%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 3.80% | | |
Senior notes, face amount | $ 350 | | |
Senior notes, effective interest rate | 2.80% | | |
Senior Notes | 2034 Senior Notes, interest rate of 4.5%, face amount $300, maturing October 1, 2034 (effective interest rate of 4.1%) | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 4.50% | | |
Senior notes, face amount | $ 300 | | |
Senior notes, effective interest rate | 4.10% | | |
Commercial Paper | | | |
Debt Instrument [Line Items] | | | |
Commercial paper | $ 1,599 | | $ 938 |
Mortgages and Other | | | |
Debt Instrument [Line Items] | | | |
Mortgages and other | $ 18 | | $ 0 |
Mortgages and Other | Maximum | | | |
Debt Instrument [Line Items] | | | |
Senior notes, stated interest rate | 3.70% | | |