Name:	prim_ConcentrationRiskMinimumPercentageOfRevenuesGeneratedBySpecifiedNumberOfTopCustomers
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Represents the number of calendar years in which top customers typically generate minimum specified percentage of revenue.

No definition available.

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Represents the number of customers who typically contribute accounts receivable in excess of a specified percentage.

No definition available.

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Represents the number of top customers who typically generate revenue in excess of a specified percentage of total revenues for the entity and consist of a different group of customers in each year.

No definition available.

Name:	prim_ConcentrationRiskNumberOfTopCustomers
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Data Type:	xbrli:integerItemType
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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.

No definition available.

Name:	us-gaap_ConcentrationRiskLineItems
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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 18

-URI http://asc.fasb.org/extlink&oid=51801978&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=51801978&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=49121117&loc=d3e13537-108611

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Data Type:	num:percentItemType
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Aggregate revenue during the period from services rendered in the normal course of business, after deducting allowances and discounts.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(d))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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Data Type:	xbrli:monetaryItemType
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Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
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Period Type:

Name:	us-gaap_MajorCustomersAxis=prim_TopTenCustomersMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_MajorCustomersAxis=prim_LargeGasPipelineCompanyMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_MajorCustomersAxis=prim_TXDOTMember
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Data Type:	na
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Name:	us-gaap_MajorCustomersAxis=prim_PetrochemicalOperatingCompanyMember
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Data Type:	na
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Name:	us-gaap_MajorCustomersAxis=prim_OneCustomerMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_AccountsReceivableMember
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