Number of persons employed by the Entity

No definition available.

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- Definition

Entity Number of Employees, Field Personnel

+ References

No definition available.

+ Details

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- Definition

The percentage of the number of employees.

+ References

No definition available.

+ Details

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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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- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

+ References

No definition available.

+ Details

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- Definition

Percentage of contributions required of employer under collective bargaining arrangement to total contributions required under all collective bargaining arrangements for pension and other postretirement plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 5
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947

+ Details

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- Definition

Amount of contributions made to multiemployer plan by employer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450702-114947

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 5
-Subparagraph (e)(1)
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450657-114947

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 80
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450691-114947

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Balance Type:	credit
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Employee Benefit Plans - Narrative (Details) $ in Millions	12 Months Ended
Employee Benefit Plans - Narrative (Details) $ in Millions	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Defined Contribution Plan Disclosure [Line Items]
Employer matching contributions	$ 2.3	$ 1.8	$ 1.8
Number of employees	1,740
Entity number of employees, field personnel	1,450
Contributions	$ 1.5	$ 1.2	$ 1.5
Red Zone
Defined Contribution Plan Disclosure [Line Items]
Multiemployer plan, collective-bargaining arrangement, percentage of contributions required for multiple collective-bargaining arrangements	65.00%
Orange Zone
Defined Contribution Plan Disclosure [Line Items]
Multiemployer plan, collective-bargaining arrangement, percentage of contributions required for multiple collective-bargaining arrangements	80.00%
Yellow Zone
Defined Contribution Plan Disclosure [Line Items]
Multiemployer plan, collective-bargaining arrangement, percentage of contributions required for multiple collective-bargaining arrangements	80.00%
Yellow Zone \| Minimum
Defined Contribution Plan Disclosure [Line Items]
Multiemployer plan, collective-bargaining arrangement, percentage of contributions required for multiple collective-bargaining arrangements	80.00%
Union Members \| Nevada, Arizona, California, and Hawaii
Defined Contribution Plan Disclosure [Line Items]
Number of employees	255
Number of employees, percent	15.00%