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Earnings Per Share - Additional Information (Detail) - $ / shares shares in Millions | 1 Months Ended | 3 Months Ended | 9 Months Ended
--- | --- | --- | ---
Jul. 31, 2015 | Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |  |
Basic average number of share |  |  | 19 |  | 7
Weighted average number of shares outstanding |  | 438 | 427 | 438 | 414
Weighted Average [Member] |  |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |  |
Number of anti-dilutive securities |  |  | 8 |  | 3
RTI [Member] |  |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |  |
Number of common stock shares issued in a part of acquisition | 29 |  |  |  |
Weighted average number of shares outstanding |  |  | 29 |  | 29
Mandatory Convertible Notes [Member] |  |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |  |
Number of anti-dilutive securities |  | 26 | 26 | 26 | 26
Equity Unit Purchase Agreements [Member] |  |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |  |
Number of anti-dilutive securities |  |  |  | 8 | 9
Stock Options [Member] |  |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |  |
Weighted average exercise price of options |  |  |  | $ 38.16 | $ 38.28
Convertible Notes [Member] |  |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] |  |  |  |  |
Number of anti-dilutive securities |  |  |  | 9 |

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- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Antidilution -URI http://asc.fasb.org/extlink&oid=6505113 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Diluted Earnings Per Share -URI http://asc.fasb.org/extlink&oid=6510752 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Contingent Stock Agreement -URI http://asc.fasb.org/extlink&oid=6508534 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
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