Stock-Based Compensation (Stock Options Outstanding and Exercisable by Exercise Price) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2016	Jul. 16, 2014
Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Number of stock options outstanding	11,911,647
Number of stock options exercisable	7,352,349
Weighted average remaining contractual life of outstanding stock options (years)	4 years 6 months 26 days
Intrinsic value of stock options outstanding	$ 236
Weighted average remaining contractual life of exercisable stock options (years)	3 years 7 months 21 days
Intrinsic value of stock options exercisable	$ 189
Share price	$ 63.62	$ 60.85
$5 to $9.99 [Member]
Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Exercise price range, lower range limit	5
Exercise price range, upper range limit	$ 9.99
Number of stock options outstanding	301,305
Number of stock options exercisable	301,305
Stock options outstanding, weighted average exercise price	$ 5.28
Stock options exercisable, weighted average exercise price	$ 5.28
Weighted average remaining contractual life of outstanding stock options (years)	4 months 6 days
$10 to $19.99 [Member]
Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Exercise price range, lower range limit	$ 10
Exercise price range, upper range limit	$ 19.99
Number of stock options outstanding	320,447
Number of stock options exercisable	320,447
Stock options outstanding, weighted average exercise price	$ 14.12
Stock options exercisable, weighted average exercise price	$ 14.12
Weighted average remaining contractual life of outstanding stock options (years)	1 year 7 months 28 days
$20 to $29.99 [Member]
Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Exercise price range, lower range limit	$ 20
Exercise price range, upper range limit	$ 29.99
Number of stock options outstanding	2,415,271
Number of stock options exercisable	2,415,271
Stock options outstanding, weighted average exercise price	$ 27.72
Stock options exercisable, weighted average exercise price	$ 27.72
Weighted average remaining contractual life of outstanding stock options (years)	2 years 10 months 6 days
$30 to $39.99 [Member]
Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Exercise price range, lower range limit	$ 30
Exercise price range, upper range limit	$ 39.99
Number of stock options outstanding	1,314,623
Number of stock options exercisable	1,314,623
Stock options outstanding, weighted average exercise price	$ 34.13
Stock options exercisable, weighted average exercise price	$ 34.13
Weighted average remaining contractual life of outstanding stock options (years)	3 years 9 months
$40 to $49.99 [Member]
Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Exercise price range, lower range limit	$ 40
Exercise price range, upper range limit	$ 49.99
Number of stock options outstanding	3,767,119
Number of stock options exercisable	1,487,149
Stock options outstanding, weighted average exercise price	$ 45.01
Stock options exercisable, weighted average exercise price	$ 44.41
Weighted average remaining contractual life of outstanding stock options (years)	5 years 6 months 15 days
$50 to $59.99 [Member]
Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Exercise price range, lower range limit	$ 50
Exercise price range, upper range limit	$ 59.99
Number of stock options outstanding	1,785,593
Number of stock options exercisable	490,242
Stock options outstanding, weighted average exercise price	$ 59.54
Stock options exercisable, weighted average exercise price	$ 59.54
Weighted average remaining contractual life of outstanding stock options (years)	6 years 11 days
$60 to $69.99 [Member]
Stock Options Outstanding And Exercisable By Exercise Price Range [Line Items]
Exercise price range, lower range limit	$ 60
Exercise price range, upper range limit	$ 69.99
Number of stock options outstanding	2,007,289
Number of stock options exercisable	1,023,312
Stock options outstanding, weighted average exercise price	$ 65.77
Stock options exercisable, weighted average exercise price	$ 65.89
Weighted average remaining contractual life of outstanding stock options (years)	5 years 1 month 21 days

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Price of a single share of a number of saleable stocks of a company.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

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-Publisher FASB
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Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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