Leases (Narrative) (Details) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Short-term lease cost	$ 34
Product concentration risk \| Revenues
Lessee, Lease, Description [Line Items]
Percentage of equipment rental revenue	85.00%
Minimum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Renewal Term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Renewal Term	5 years

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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+ References

No definition available.

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- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

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Amount of short-term lease cost, excluding expense for lease with term of one month or less.

+ References

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