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Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016
Significant Accounting Policies [Line Items] |  |
Changes in assumptions and experience gains and losses | Greater than 10% |
Period of benefit obligation in current liabilities | Next twelve months |
Research and develepment costs | $ 522 | $ 460
Minimum [Member] |  |
Significant Accounting Policies [Line Items] |  |
Amortizable intangible assets, estimated useful life | 4 years |
Minimum [Member] | Building [Member] |  |
Significant Accounting Policies [Line Items] |  |
Annual rates of depreciation on fixed assets | 2.50% |
Minimum [Member] | General Purpose Equipment [Member] |  |
Significant Accounting Policies [Line Items] |  |
Annual rates of depreciation on fixed assets | 7.00% |
Minimum [Member] | Special Purpose Equipment [Member] |  |
Significant Accounting Policies [Line Items] |  |
Annual rates of depreciation on fixed assets | 10.00% |
Maximum [Member] |  |
Significant Accounting Policies [Line Items] |  |
Amortizable intangible assets, estimated useful life | 15 years |
Maximum [Member] | Building [Member] |  |
Significant Accounting Policies [Line Items] |  |
Annual rates of depreciation on fixed assets | 5.00% |
Maximum [Member] | General Purpose Equipment [Member] |  |
Significant Accounting Policies [Line Items] |  |
Annual rates of depreciation on fixed assets | 10.00% |
Maximum [Member] | Special Purpose Equipment [Member] |  |
Significant Accounting Policies [Line Items] |  |
Annual rates of depreciation on fixed assets | 33.00% |

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- Definition Changes in assumptions and experience gains and losses recognized in income. + References No definition available. + Details
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- Definition Period of benefit obligation in current liabilities. + References No definition available. + Details
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- Definition Property plant and equipment depreciation rate. + References No definition available. + Details
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- Definition Significant Accounting Policies [Line Items] + References No definition available. + Details
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- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 730 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6420194&loc=d3e21568-108373 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 985 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756 + Details
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Balance Type: | debit
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- Details
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- Details
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- Details
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- Details
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