Name:	prim_AdjustedNotionalAmountPercentageOfPrincipalPaymentsOnTermLoan
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Data Type:	num:percentItemType
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Period Type:	duration

Represents the percentage of debt outstanding in which the interest rate was effectively exchanged

No definition available.

Name:	prim_InterestRateSwapAgreementPercentageOfDebtOutstandingInWhichInterestExchanged
Namespace Prefix:	prim_
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Represents the number of instruments used for trading.

No definition available.

Name:	prim_NumberOfInstrumentsUsedForTrading
Namespace Prefix:	prim_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

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_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Nominal or face amount used to calculate payments on the derivative liability.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Name:	us-gaap_DerivativeLiabilityNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

The number of derivative instruments of a particular group held by the entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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