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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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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.

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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/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
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-URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9054-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 825
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-Section 50
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI https://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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Name:	srt_MajorCustomersAxis=prim_TopTenCustomersMember
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