Commitments and Contingencies (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018 USD ($) property	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) property	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Other Commitments [Line Items]
Number of Leased Properties Owned by Related Parties \| property	2		2
Costs and Expenses, Related Party	$ 320	$ 320	$ 630	$ 630
Operating Leases, Future Minimum Payments Due	27,700		27,700
Self Insurance Reserve	1,900		1,900		$ 2,080
Estimated Insurance Recoveries	15,117		15,117		12,702
Letters of Credit Outstanding, Amount	4,390		4,390		$ 4,410
Deferred Compensation Liability, Noncurrent	$ 6,080		$ 6,080

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Costs of sales and operating expenses for the period incurred from transactions with related parties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
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Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable beyond one year (or the operating cycle, if longer).

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No definition available.

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Carrying amount as of the balance sheet date of amounts expected to be recovered under the terms of insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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No definition available.

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Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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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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Carrying amount (including both current and noncurrent portions) of accrued known and estimated losses incurred as of the balance sheet date for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property.

+ References

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