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Stock Incentive Plans (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2017
Stock Incentive Awards Units Outstanding (Roll Forward) |  |  |  |
Units outstanding at beginning of period (in shares) | 55.1 |  |  |
Granted (in shares) | 16.7 |  |  |
Settled (in shares) | (16.3) |  |  |
Forfeited or expired (in shares) | (2.6) |  |  |
Units outstanding at end of period (in shares) | 52.9 | 55.1 |  |
Stock Incentive Awards Weighted Average Grant Date Fair Value (Per Share) [Roll Forward] |  |  |  |
Weighted-average grant date fair value, Units outstanding at beginning of period (in dollars per share) | $ 19.77 |  |  |
Weighted-average grant date fair value, granted (in dollars per share) | 26.75 |  |  |
Weighted-average grant date fair value, settled (in dollars per share) | 24.65 |  |  |
Weighted-average grant date fair value, forfeited or expired (in dollars per share) | 26.67 |  |  |
Weighted-average grant date fair value, Units outstanding at end of period (in dollars per share) | $ 19.77 | $ 19.77 |  | $ 21.75
Remaining Contractual Term [Abstract] |  |  |  |
Weighted Average Remaining Contractual Terms in years, Outstanding | 2 years | 2 years 6 months |  |
Compensation expense | $ 585 | $ 627 | $ 422 |
Unrecognized compensation expense |  |  |  | $ 278
Weighted-average period for total unrecognized compensation expense for nonvested equity awards | 1 year 8 months 12 days |  |  |
Fair value of stock incentive awards vested | $ 421 | $ 325 | $ 228 |
Restricted Stock Units (RSUs) [Member] |  |  |  |
Stock Incentive Plans Narratives [Abstract] |  |  |  |
Service period | 3 years |  |  |
Performance Share Units (PSUs) [Member] |  |  |  |
Stock Incentive Plans Narratives [Abstract] |  |  |  |
Performance period | 3 years |  |  |
Stock options [Member] |  |  |  |
Stock Incentive Plans Narratives [Abstract] |  |  |  |
Expiration period | 10 years |  |  |
Remaining Contractual Term [Abstract] |  |  |  |
Dividend yield | 4.43% |  | 4.60% |
Expected volatility | 25.00% |  | 26.10% |
Risk-free interest rate | 1.97% |  | 2.00% |
Expected option life | 5 years 10 months 2 days |  | 6 years 7 months 2 days |
Performance-based Employee Stock Options [Member] |  |  |  |
Stock Incentive Plans Narratives [Abstract] |  |  |  |
Service period | 55 months |  |  |
Service-based Employee Stock Options [Member] | Minimum [Member] |  |  |  |
Stock Incentive Plans Narratives [Abstract] |  |  |  |
Service period | 19 months |  |  |
Service-based Employee Stock Options [Member] | Maximum [Member] |  |  |  |
Stock Incentive Plans Narratives [Abstract] |  |  |  |
Service period | 3 years |  |  |
Restricted Stock Awards (RSAs) [Member] |  |  |  |
Stock Incentive Plans Narratives [Abstract] |  |  |  |
Service period | 3 years |  |  |

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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Definition The weighted average grant date fair value of options and equity instruments other than options issued during the period, including both vested and nonvested instruments. + References No definition available. + Details
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- Definition Number of options and equity Instruments other than options outstanding, including both vested and non-vested instruments. + References No definition available. + Details
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- Definition The weighted average grant date fair value of options and equity instruments other than options settled during the period. + References No definition available. + Details
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- Definition Share-based Compensation Arrangement by Share-based Payment Award, Option and Non-Option Equity Instruments, Outstanding [Roll Forward] + References No definition available. + Details
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- Definition Number of option and non-option equity instruments exercised by participants. + References No definition available. + Details
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- Definition Number of shares under option and non-option equity instrument agreements that were either cancelled or expired. + References No definition available. + Details
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- Definition Net number of option and non-option equity instruments granted to participants. + References No definition available. + Details
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- Definition The weighted average fair value of nonvested awards on equity-based plans including option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units. + References No definition available. + Details
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- Definition Weighted average fair value as of the grant date of stock options and non-option equity instruments that were not exercised or put into effect as a result of the occurrence of a terminating event. + References No definition available. + Details
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- Definition Weighted average remaining contractual term for option and non-option equity-based awards, 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 Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5047-113901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Unrecognized cost of unvested share-based compensation awards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iii) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iv) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Weighted average expected volatility rate of share-based compensation awards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(ii) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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