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Acquisitions and Divestitures - 2015 Acquisitions (Detail) $ / shares in Units, € in Millions |  |  |  | 1 Months Ended | 3 Months Ended | 4 Months Ended | 5 Months Ended | 12 Months Ended | 14 Months Ended |  |
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Oct. 05, 2016 shares | Jul. 23, 2015 shares | Jul. 22, 2015 shares | Jul. 31, 2015 USD ($) $ / shares shares | Mar. 31, 2015 USD ($) employee | Mar. 31, 2015 EUR (€) employee | Dec. 31, 2017 USD ($) $ / shares | Sep. 30, 2017 USD ($) | Jun. 30, 2017 USD ($) $ / shares | Mar. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Sep. 30, 2016 USD ($) | Jun. 30, 2016 USD ($) | Mar. 31, 2016 USD ($) | Apr. 29, 2016 USD ($) employee | Dec. 31, 2015 USD ($) | Dec. 31, 2017 USD ($) $ / shares shares | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($) Tranche company | Dec. 31, 2014 USD ($) employee | Oct. 04, 2016 shares | Sep. 30, 2015 USD ($) | Sep. 30, 2015 EUR (€) | Mar. 06, 2015 $ / shares
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Goodwill |  |  |  |  |  |  | $ 4,535,000,000 |  |  |  | $ 5,148,000,000 |  |  |  |  | $ 5,249,000,000 | $ 4,535,000,000 | $ 5,148,000,000 | $ 5,249,000,000 |  |  |  |  |
Common stock conversion transaction value |  |  |  |  |  |  | 0 |  |  |  | 0 |  |  |  |  | 870,000,000 | 0 | 0 | 870,000,000 |  |  |  |  |
Common stock sold per share (usd per share) | $ / shares |  |  |  |  |  |  |  |  | $ 35.91 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sales revenue, goods, net |  |  |  |  |  |  | $ 3,271,000,000 | $ 3,236,000,000 | $ 3,261,000,000 | $ 3,192,000,000 | $ 2,967,000,000 | $ 3,138,000,000 | $ 3,234,000,000 | $ 3,055,000,000 |  |  | 12,960,000,000 | 12,394,000,000 | 12,413,000,000 |  |  |  |  |
Adjusted EBITDA |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 2,144,000,000 | $ 2,063,000,000 | 1,894,000,000 |  |  |  |  |
TITAL |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash paid for business acquisition |  |  |  |  | $ 204,000,000 | € 188 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition transaction cost |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,000,000 | € 1 |
Number of employees | employee |  |  |  |  | 650 | 650 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Goodwill |  |  |  |  | $ 118,000,000 |  |  |  |  |  |  |  |  | 117,000,000 |  |  |  |  |  |  |  |  |  |
Goodwill, purchase accounting adjustments |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,000,000 |  |  |  |  |  |  |  |  |  |
RTI |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of employees | employee |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 330 |  |  |  |  |  |  |  |  |
Goodwill |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 298,000,000 |  |  | 298,000,000 |  |  |  |  |
Goodwill deductible for income tax purpose |  |  |  |  | $ 0 |  |  |  |  |  |  |  |  |  |  | 0 |  |  | $ 0 |  |  |  |  |
Common stock conversion transaction value |  |  |  | $ 870,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock sold per share (usd per share) | $ / shares |  |  |  | $ 9.96 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 14.48
Debt instrument, convertible, conversion price | $ / shares |  |  |  | $ 2.8315 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of common stock shares issued in a part of acquisition (in shares) | shares | 29,000,000 | 87,397,414 | 29,132,471 | 29,132,471 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 87,000,000 |  |  |
Acquisition price per share (USD per share) | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 41
Professional fees and costs |  |  |  | $ 25,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Professional fees and costs, after tax |  |  |  | $ 19,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sales revenue, goods, net |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 20,000,000 | 309,000,000 |  |  |  |  |  |  |  |
Synergy from merger and acquisition, number of companies | company |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 |  |  |  |  |
RTI | Convertible Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, convertible, conversion price | $ / shares |  |  |  | $ 28.1596 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of repayment tranches | Tranche |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 |  |  |  |  |
Debt instrument, amount received upon maturity per one thousand dollars in principal amount of notes held |  |  |  | $ 1,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
RTI | Tranche Due December 2015 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt due within one year |  |  |  | 115,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
RTI | Tranche Due October 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt due within one year |  |  |  | $ 403,000,000 |  |  |  |  |  |  |  |  |  |  |  | 403,000,000 |  |  | $ 403,000,000 |  |  |  |  |
RTI | 1.63% Convertible Notes, Due 2019 | Convertible Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, convertible, conversion price | $ / shares |  |  |  |  |  |  | $ 28.1596 |  |  |  |  |  |  |  |  |  | $ 28.1596 |  |  |  |  |  |  |
Conversion of notes to common stock (in shares) | shares |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 14,294,000 |  |  |  |  |  |  |
Debt instrument, convertible, conversion rate per bond |  |  |  |  |  |  | 0.0355119 |  |  |  |  |  |  |  |  |  | 0.0355119 |  |  |  |  |  |  |
RTI | Customer Relationships |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Finite-lived intangible assets acquired |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 37,000,000 |  |  |  |  |
Weighted average amortization period of intangible asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 20 years |  |  |  |  |
Maximum | RTI |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Adjusted EBITDA |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 21,000,000 |  |  |  |  |  |  |  |
RTI |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of employees | employee |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,600 |  |  |  |
Sales revenue, goods, net |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 794,000,000 |  |  |  |

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