Leases - Other Information (Details) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating cash flows for operating leases	$ 33
Financing cash flows for finance leases	$ 4
Weighted-average remaining lease term (in years)
Operating leases, weighted-average lease term	9 years 9 months 18 days
Finance leases, weighted-average lease term	3 years
Weighted-average discount rate
Operating leases, weighted-average discount rate	4.50%
Finance leases, weighted-average discount rate	2.20%

Lease, Weighted Average Remaining Lease Term [Abstract]

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Leases, Weighted Average Discount Rate, Percent [Abstract]

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- Definition

Amount of cash outflow for principal payment on finance lease.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
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Weighted average discount rate for finance lease calculated at point in time.

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Weighted average remaining lease term for finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

+ References

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-Publisher FASB
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Weighted average discount rate for operating lease calculated at point in time.

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Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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