Leased assets.

No definition available.

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- Definition

Term of lessee's 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/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

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

+ References

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of operating lease expense. Excludes sublease income.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918638-209977

+ Details

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Balance Type:	debit
Period Type:	duration

- Details

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Leases - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2016
Leased Assets [Line Items]
Operating lease expense	$ 36,041	$ 45,949	$ 35,770
Vehicles and Equipment \| Minimum
Leased Assets [Line Items]
Capital lease, term of contract		1 year
Vehicles and Equipment \| Maximum
Leased Assets [Line Items]
Capital lease, term of contract		5 years
Building and Equipment \| Minimum
Leased Assets [Line Items]
Operating lease, term of contract		1 month
Building and Equipment \| Maximum
Leased Assets [Line Items]
Operating lease, term of contract		10 years