Commitments and Contingencies (Details)	Mar. 31, 2018 USD ($) letter_of_credit
Debt Instrument [Line Items]
Number of letters of credit provided as collateral \| letter_of_credit	2
Standby Letters of Credit
Debt Instrument [Line Items]
Current borrowing capacity	$ 18,000,000
Credit Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility	75,000,000.0
Unused portion of facility	60,000,000
Credit Facility \| Letter of Credit Facility
Debt Instrument [Line Items]
Line of credit facility	40,000,000.0
Credit Facility \| Swingline Facility
Debt Instrument [Line Items]
Line of credit facility	10,000,000.0
Collateral for Workers' Compensation Obligation \| Line of Credit Facility
Debt Instrument [Line Items]
Line of credit facility	5,000,000.0
Unused portion of facility	$ 3,000,000

Number of Letters of Credit

No definition available.

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- Definition

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.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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Namespace Prefix:	us-gaap_
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Period Type:	instant

- Details

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Namespace Prefix:
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- Details

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- Details

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- Details

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- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
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- Details

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