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Note 15 - Employee Benefit Plans (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 1,800	$ 1,800	$ 1,300
Entity Number of Employees	1,684
Multiemployer Plan, Period Contributions	$ 12,638	14,534	10,808
Individually Insignificant Multiemployer Pension Costs [Member]
Multiemployer Plan, Period Contributions	$ 1,200	$ 1,500	$ 900
Red Zone [Member]
Multiemployer Plans, Collective-Bargaining Arrangement, Percentage of Contributions	65.00%
Orange Zone [Member]
Multiemployer Plans, Collective-Bargaining Arrangement, Percentage of Contributions	80.00%
Yellow Zone [Member]
Multiemployer Plans, Collective-Bargaining Arrangement, Percentage of Contributions	80.00%
Yellow Zone [Member] | Minimum [Member]
Multiemployer Plans, Collective-Bargaining Arrangement, Percentage of Contributions	80.00%
Field Personnel [Member]
Entity Number of Employees	1,364
Union Members [Member] | Nevada, Arizona, California, and Hawaii [Member]
Entity Number of Employees	366
Number of Employees, Percent	22.00%

X

- Definition

Number of persons employed by the Entity

+ References

No definition available.

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- Definition

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+ References

No definition available.

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X

- Definition

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

+ References

No definition available.

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- Definition

Amount of contributions made to multiemployer plans by the employer. A multiemployer plan is a pension or postretirement benefit 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 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 9
-URI http://asc.fasb.org/extlink&oid=65877416&loc=SL14450691-114947

Reference 3: 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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X

- Definition

Percentage of contributions required by a collective bargaining arrangement to contributions required by all collective bargaining arrangements related to a pension or postretirement benefit 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

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