Debt - Additional Information (Detail) € in Millions, £ in Millions, SFr in Millions | Oct. 06, 2015USD ($) | Jun. 11, 2015EUR (€) | Mar. 30, 2015USD ($) | Mar. 20, 2015USD ($) | Mar. 20, 2015EUR (€) | Mar. 06, 2015USD ($) | Mar. 31, 2015USD ($) | Sep. 30, 2015USD ($) | Sep. 30, 2014USD ($) | Sep. 21, 2015CHF (SFr) | Mar. 30, 2015CHF (SFr) | Mar. 06, 2015EUR (€) | Mar. 06, 2015GBP (£) | Dec. 31, 2014USD ($) | Dec. 31, 2013 |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Revolving credit facility debt covenant | | | | | | | | $ 24,600,000,000 | | | | | | | |
Repayment of debt | | | | | | | | 4,543,000,000 | $ 2,524,000,000 | | | | | | |
Cash tender offer amount | | | | $ 2,500,000,000 | | | | | | | | | | | |
Loss on extinguishment of debt | | | | | | | | $ (708,000,000) | $ (493,000,000) | | | | | | |
Weighted-average interest rate | | | | | | | | 3.50% | | | | | | 4.30% | 4.80% |
Fair value of total debt | | | | | | | | $ 16,874,000,000 | | | | | | $ 18,463,000,000 | |
Carrying value of total debt | | | | | | | | 16,359,000,000 | | | | | | 16,700,000,000 | |
International Subsidiaries | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Revolving credit facility, maximum borrowing capacity | | | | | | | | 1,900,000,000 | | | | | | 2,100,000,000 | |
Line of credit facility outstanding amount | | | | | | | | 292,000,000 | | | | | | $ 204,000,000 | |
Revolving Credit Facility, October 11, 2018 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Revolving credit facility, maximum borrowing capacity | | | | | | | | $ 4,500,000,000 | | | | | | | |
Revolving credit facility expiration date | | | | | | | | Oct. 11, 2018 | | | | | | | |
Revolving credit facility debt covenant terms | | | | | | | | Minimum shareholders' equity of at least $24.6 billion, excluding accumulated other comprehensive earnings / (losses) and the cumulative effects of any changes in accounting principles. | | | | | | | |
Revolving credit facility debt covenant compliance | | | | | | | | At September 30, 2015, we complied with the covenant | | | | | | | |
Total shareholders' equity, excluding accumulated other comprehensive earnings / (losses) | | | | | | | | $ 39,500,000,000 | | | | | | | |
Line of credit facility outstanding amount | | | | | | | | $ 0 | | | | | | | |
Tender Offer | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Loss on extinguishment of debt | | | | | | | $ (708,000,000) | | | | | | | | |
Tender Offer | 6.500% Notes due in August 2017 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument interest rate | | | | 6.50% | | | | | | | | | | | |
Debt instrument repurchased, principal amount | | | | $ 102,000,000 | | | | | | | | | | | |
Debt instrument expiration | | | | | | | | 2017-08 | | | | | | | |
Tender Offer | 6.125% Notes due in February 2018 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument interest rate | | | | 6.125% | | | | | | | | | | | |
Debt instrument repurchased, principal amount | | | | $ 115,000,000 | | | | | | | | | | | |
Debt instrument expiration | | | | | | | | 2018-02 | | | | | | | |
Tender Offer | 6.125% Notes due in August 2018 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument interest rate | | | | 6.125% | | | | | | | | | | | |
Debt instrument repurchased, principal amount | | | | $ 80,000,000 | | | | | | | | | | | |
Debt instrument expiration | | | | | | | | 2018-08 | | | | | | | |
Tender Offer | 5.375% Notes due in February 2020 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument interest rate | | | | 5.375% | | | | | | | | | | | |
Debt instrument repurchased, principal amount | | | | $ 691,000,000 | | | | | | | | | | | |
Debt instrument expiration | | | | | | | | 2020-02 | | | | | | | |
Tender Offer | 6.500% Notes due in November 2031 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument interest rate | | | | 6.50% | | | | | | | | | | | |
Debt instrument repurchased, principal amount | | | | $ 201,000,000 | | | | | | | | | | | |
Debt instrument expiration | | | | | | | | 2031-11 | | | | | | | |
Tender Offer | 7.000% Notes due in August 2037 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument interest rate | | | | 7.00% | | | | | | | | | | | |
Debt instrument repurchased, principal amount | | | | $ 26,000,000 | | | | | | | | | | | |
Debt instrument expiration | | | | | | | | 2037-08 | | | | | | | |
Tender Offer | 6.875% Notes due in February 2038 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument interest rate | | | | 6.875% | | | | | | | | | | | |
Debt instrument repurchased, principal amount | | | | $ 71,000,000 | | | | | | | | | | | |
Debt instrument expiration | | | | | | | | 2038-02 | | | | | | | |
Tender Offer | 6.875% Notes due in January 2039 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument interest rate | | | | 6.875% | | | | | | | | | | | |
Debt instrument repurchased, principal amount | | | | $ 69,000,000 | | | | | | | | | | | |
Debt instrument expiration | | | | | | | | 2039-01 | | | | | | | |
Tender Offer | 6.500% Notes due in February 2040 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument interest rate | | | | 6.50% | | | | | | | | | | | |
Debt instrument repurchased, principal amount | | | | $ 1,143,000,000 | | | | | | | | | | | |
Debt instrument expiration | | | | | | | | 2040-02 | | | | | | | |
Cash Flow Hedges | Tender Offer | Interest rate contracts | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Interest expense | | | | $ 5,000,000 | | | | | | | | | | | |
Euro notes | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Repayment of debt | € | | € 400 | | | | | | | | | | | | | |
Swiss franc notes | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | | | | | | | 694,000,000 | | | SFr 400 | SFr 675 | | | | |
Net proceeds from issuance of notes | | | $ 675,000,000 | | | | | | | | | | | | |
Discounts and deferred financing costs | | | 2,000,000 | | | | | | | | | | | | |
Swiss franc notes | Subsequent Event | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | $ 414,000,000 | | | | | | | | | | | | | | |
Net proceeds from issuance of notes | 410,000,000 | | | | | | | | | | | | | | |
Discounts and deferred financing costs | 1,000,000 | | | | | | | | | | | | | | |
0.000% Fixed Rate Notes, mature on March 30, 2017 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | | | $ 180,000,000 | | | | | | | | SFr 175 | | | | |
Debt instrument, fixed interest rate | | | 0.00% | | | | | | | | 0.00% | | | | |
Deb instrument maturity Year | | | | | | | | Mar. 30, 2017 | | | | | | | |
0.625% Fixed Rate Notes, mature on December 30, 2021 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | | | $ 308,000,000 | | | | | | | | SFr 300 | | | | |
Debt instrument, fixed interest rate | | | 0.625% | | | | | | | | 0.625% | | | | |
Deb instrument maturity Year | | | | | | | | Dec. 30, 2021 | | | | | | | |
1.125% Fixed Rate Notes, mature on December 30, 2025 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | | | $ 206,000,000 | | | | | | | | SFr 200 | | | | |
Debt instrument, fixed interest rate | | | 1.125% | | | | | | | | 1.125% | | | | |
Deb instrument maturity Year | | | | | | | | Dec. 30, 2025 | | | | | | | |
Euro-denominated notes | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | € | | | | | | | | | | | | € 2,000 | | | |
Euro-denominated notes | 6.250% Senior Notes | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Repayment of debt | € | | | | | € 850 | | | | | | | | | | |
Debt instrument interest rate | | | | 6.25% | | | | | | | | | | | |
Euro-denominated and British pound sterling-denominated notes | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | | | | | | $ 2,800,000,000 | $ 2,800,000,000 | | | | | | | | |
Net proceeds from issuance of notes | | | | | | 2,890,000,000 | | | | | | | | | |
Discounts and deferred financing costs | | | | | | 29,000,000 | | | | | | | | | |
British pound sterling-denominated notes | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | £ | | | | | | | | | | | | | £ 450 | | |
1.000% Fixed rate notes, due March 7, 2022 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | | | | | | $ 537,000,000 | | | | | | € 500 | | | |
Debt instrument, fixed interest rate | | | | | | 1.00% | | | | | | 1.00% | 1.00% | | |
Deb instrument maturity Year | | | | | | | | Mar. 7, 2022 | | | | | | | |
1.625% Fixed rate notes due , March 8, 2027 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | | | | | | $ 805,000,000 | | | | | | € 750 | | | |
Debt instrument, fixed interest rate | | | | | | 1.625% | | | | | | 1.625% | 1.625% | | |
Deb instrument maturity Year | | | | | | | | Mar. 8, 2027 | | | | | | | |
2.375% Fixed rate notes, due March 6, 2035 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | | | | | | $ 805,000,000 | | | | | | € 750 | | | |
Debt instrument, fixed interest rate | | | | | | 2.375% | | | | | | 2.375% | 2.375% | | |
Deb instrument maturity Year | | | | | | | | Mar. 6, 2035 | | | | | | | |
3.875% Fixed rate notes, due March 6, 2045 | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | | | | | | $ 667,000,000 | | | | | | € 450 | | | |
Debt instrument, fixed interest rate | | | | | | 3.875% | | | | | | 3.875% | 3.875% | | |
Deb instrument maturity Year | | | | | | | | Mar. 6, 2045 | | | | | | | |
Fixed Rate Zero Point Six Two Five Percentage Notes Due October Sixth Twenty Twenty | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | SFr | | | | | | | | | | SFr 135 | | | | | |
Debt instrument, fixed interest rate | | | | | | | | | | 0.625% | | | | | |
Deb instrument maturity Year | | | | | | | | Oct. 6, 2020 | | | | | | | |
Fixed Rate Zero Point Six Two Five Percentage Notes Due October Sixth Twenty Twenty | Subsequent Event | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | 140,000,000 | | | | | | | | | | | | | | |
Fixed Rate One Point One Two Five Percentage Notes Due December Twenty First Twenty Twenty Third | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | SFr | | | | | | | | | | SFr 265 | | | | | |
Debt instrument, fixed interest rate | | | | | | | | | | 1.125% | | | | | |
Deb instrument maturity Year | | | | | | | | Dec. 21, 2023 | | | | | | | |
Fixed Rate One Point One Two Five Percentage Notes Due December Twenty First Twenty Twenty Third | Subsequent Event | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Debt instrument, principal amount | $ 274,000,000 | | | | | | | | | | | | | | |
Commercial Paper | Minimum | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Commercial paper, Maturity period | | | | | | | | 1 day | | | | | | | |
Commercial Paper | Maximum | | | | | | | | | | | | | | | |
Debt Instrument [Line Items] | | | | | | | | | | | | | | | |
Commercial paper, Maturity period | | | | | | | | 55 days | | | | | | | |