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Taxes on Income - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Income Tax [Line Items] |  |  |  |
Provisional charge for one-time transition tax related to Tax Cuts and Jobs Act of 2017 | $ 5,347 | $ 0 | $ 0 |
Provisional liability for one-time transition tax related to Tax Cuts and Job Act of 2017 | 5,100 |  |  |
Deferred Tax Liabilities, Undistributed Foreign Earnings | 33 | $ 2,044 |  |
Provisional current liability for one-time transition tax related to Tax Cuts and Jobs Act of 2017 | 545 |  |  |
Provisional noncurrent liability for one-time transition tax related to Tax Cuts and Jobs Act of 2017 | $ 4,500 |  |  |
U.S. statutory rate applied to income before taxes (as percent) | 35.00% | 35.00% | 35.00% |
Remeasurement of deferred taxes related to Tax Cuts and Jobs Act of 2017 provisional benefit | $ 779 |  |  |
Deferred tax assets on NOL carryforwards relating to foreign jurisdictions | 630 |  |  |
Deferred tax assets relating to various U.S. tax credit carryforwards and NOL carryforwards | 24 |  |  |
Income taxes paid | 4,900 | $ 1,800 | $ 1,800 |
Tax benefits relating to stock option exercises | 73 | 147 | 109 |
Unrecognized tax benefits | 1,723 | 3,494 | 3,448 | $ 3,534
Favorable net impact to income tax provision if unrecognized tax benefits were recognized | 1,600 |  |  |
Reasonably possible amount that liability for unrecognized tax benefits could decline up to in next 12 months (up to) | 165 |  |  |
Interest and penalties associated with uncertain tax positions, expense (benefit) | 183 | 134 | 102 |
Liabilities for accrued interest and penalties | 341 | 886 |  |
Unrecognized tax benefits from adjustments related to examination | 1,388 | 92 | 184 |
Proceeds from refunds |  |  | 715 |
Income tax expense (benefit) | (4,103) | $ (718) | (942) |
Foreign Jurisdiction |  |  |  |
Income Tax [Line Items] |  |  |  |
Valuation allowance on foreign NOL carryforwards | 900 |  |  |
Internal Revenue Service (IRS) |  |  |  |
Income Tax [Line Items] |  |  |  |
Income tax expense (benefit) |  |  | $ 410 |
Internal Revenue Service (IRS) |  |  |  |
Income Tax [Line Items] |  |  |  |
Income taxes paid | 2,800 |  |  |
Unrecognized tax benefits from adjustments related to examination | 234 |  |  |
2017 Tax Cuts and Jobs Act (TCJA) [Member] |  |  |  |
Income Tax [Line Items] |  |  |  |
Deferred Tax Liabilities, Undistributed Foreign Earnings | $ 2,000 |  |  |

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- Definition Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (d)(3) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible domestic operating loss carryforwards. Excludes state and local operating loss carryforwards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32621-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 25 -Paragraph 20 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=96869850&loc=d3e28680-109314 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32632-109319 + Details
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- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 6.I) -URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319 + Details
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