Stock-Based Compensation (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Stock-based compensation cost, allocation of recognized costs
Pre-tax stock-based compensation cost	$ 129	$ 123	$ 371	$ 388
Income tax benefits	(29)	(41)	(88)	(128)
Total net stock-based compensation cost	100	82	283	260
Pre-tax stock-based compensation cost increase (decrease)	6		(17)
Pre-tax stock-based compensation cost increase (decrease) related to conversion of stock-based awards of acquired entities	(1)		(4)
Stock-based compensation cost, unrecognized, related to non-vested awards	805		$ 805
Stock-based compensation cost, unrecognized, related to non-vested awards, weighted average period of recognition			2 years 6 months
Performance share units
Stock-based compensation cost, allocation of recognized costs
Pre-tax stock-based compensation cost increase (decrease)	8
Restricted stock units
Stock-based compensation cost, allocation of recognized costs
Pre-tax stock-based compensation cost increase (decrease)	(1)		$ (13)
Cost
Stock-based compensation cost, allocation of recognized costs
Pre-tax stock-based compensation cost	19	22	60	68
SG&A Expense
Stock-based compensation cost, allocation of recognized costs
Pre-tax stock-based compensation cost	95	88	264	277
Research, development and engineering
Stock-based compensation cost, allocation of recognized costs
Pre-tax stock-based compensation cost	$ 15	$ 13	$ 47	$ 43

Represents the change in the pre-tax stock-based compensation cost from the corresponding period in the prior year.

No definition available.

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- Definition

The increase (decrease) in pre-tax share-based compensation from the corresponding period of the prior year due to conversion of share-based compensation awards previously issued by acquired entities.

+ References

No definition available.

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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

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The amount of expense, net of income tax, 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.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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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.

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- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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