Stock Plans (Details 1) $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($)
Weighted-average remaining contractual life and aggregate intrinsic value of the Company's stock options outstanding, exerciseable, and vested and expected to vest
Weighted-average remaining contractual life, Outstanding	5 years 6 months
Aggregate intrinsic value, Outstanding	$ 169
Weighted-average remaining contractual life, Exercisable	4 years
Aggregate intrinsic value, Exercisable	$ 124
Weighted-average remaining contractual life, Vested and Expected to Vest	5 years 6 months
Aggregate intrinsic value, Vested and Expected to Vest	$ 168

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-SubTopic 10
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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.

+ References

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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 remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for fully vested and expected to vest options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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