XML 34 R75.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Multiemployer Plans (Details) (USD $) In Thousands, unless otherwise specified | 12 Months Ended |  | 12 Months Ended | 7 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Dec. 31, 2012 item | Dec. 31, 2011 | Dec. 31, 2010 | Nov. 30, 2011 | Dec. 31, 2012 So Cal Pipetrades Trust Funds | Dec. 31, 2011 So Cal Pipetrades Trust Funds | Dec. 31, 2010 So Cal Pipetrades Trust Funds | Dec. 31, 2012 Laborers Pension Trust Fund for Northern California | Dec. 31, 2011 Laborers Pension Trust Fund for Northern California | Dec. 31, 2010 Laborers Pension Trust Fund for Northern California | Dec. 31, 2012 Construction Laborers Pension Trust for Southern California | Dec. 31, 2011 Construction Laborers Pension Trust for Southern California | Dec. 31, 2010 Construction Laborers Pension Trust for Southern California | Dec. 31, 2012 Central Pension Fund of the International Union of Operating Engineers and Participating Employers | Dec. 31, 2011 Central Pension Fund of the International Union of Operating Engineers and Participating Employers | Dec. 31, 2010 Central Pension Fund of the International Union of Operating Engineers and Participating Employers | Dec. 31, 2010 Laborers International Union of North America National (Industrial) Pension Fund | Dec. 31, 2012 Laborers International Union of North America National (Industrial) Pension Fund | Dec. 31, 2011 Laborers International Union of North America National (Industrial) Pension Fund | Dec. 31, 2010 Laborers International Union of North America National (Industrial) Pension Fund | Dec. 31, 2012 Pipeline Industry Benefit Fund | Dec. 31, 2011 Pipeline Industry Benefit Fund | Dec. 31, 2010 Pipeline Industry Benefit Fund | Dec. 31, 2012 Boilermaker-Blacksmith National Pension Trust | Dec. 31, 2011 Boilermaker-Blacksmith National Pension Trust | Dec. 31, 2010 Boilermaker-Blacksmith National Pension Trust | Dec. 31, 2012 Northern California Pipe Trades Pension Plan | Dec. 31, 2011 Northern California Pipe Trades Pension Plan | Dec. 31, 2010 Northern California Pipe Trades Pension Plan
Multiemployer plans |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated net liability and SG & A expense in connection with the withdrawal | $ 7,500 | $ 5,000 |  | $ 7,500 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
SG&A expense related to plan | 2,500 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of pension plans in which annual contribution was made by the entity during last three years | 66 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Contributions for significant plans | 22,154 | 16,911 | 7,959 |  | 5,298 | 2,931 | 1,394 | 4,816 | 3,501 | 1,237 | 2,952 | 2,373 | 1,694 | 2,206 | 1,797 | 946 |  | 1,995 | 1,740 | 826 | 1,747 | 1,793 | 1,110 | 1,502 | 1,035 | 469 | 1,638 | 1,741 | 283
Contributions to other multiemployer plans | 7,949 | 7,271 | 4,631 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total contributions made | $ 30,103 | $ 24,182 | $ 12,590 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Temporary surcharge (as a percent) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.00% | 10.00% |  |  |  |  |  |  |  |  |  |  |
Investment losses amortization period |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 29 years |  |  |  |  |  |  |  |  |  |  |
Investment losses amortization period, before amendment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 15 years |  |  |  |  |  |  |  |  |  |  |
Investment losses smoothing period |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10 years |  |  |  |  |  |  |  |  |  |  |
Investment losses smoothing period, before amendment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5 years |  |  |  |  |  |  |  |  |  |  |

X
- Definition Represents the number of pension plans in which annual contribution was made by the entity during the last three years. + References No definition available. + Details
Name: | prim_MultiemployerPlansAnnualContributionsNumberOfPensionPlans
Namespace Prefix: | prim_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the amount of contributions made to the other multiemployer plan by all employers who participate in the plan. 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 No definition available. + Details
Name: | prim_MultiemployerPlansContributionsOtherPlans
Namespace Prefix: | prim_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the amount of contributions made to the significant multiemployer plan by all employers who participate in the plan. 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 No definition available. + Details
Name: | prim_MultiemployerPlansContributionsSignificantPlans
Namespace Prefix: | prim_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the period to amortize investment losses of the entity. + References No definition available. + Details
Name: | prim_MultiemployerPlansInvestmentLossesAmortizationPeriod
Namespace Prefix: | prim_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the period, before amendment, to amortize investment losses of the entity. + References No definition available. + Details
Name: | prim_MultiemployerPlansInvestmentLossesAmortizationPeriodBeforeAmendment
Namespace Prefix: | prim_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the smoothing period to recognize investment losses for funding purpose. + References No definition available. + Details
Name: | prim_MultiemployerPlansInvestmentLossesSmoothingPeriod
Namespace Prefix: | prim_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the smoothing period, before amendment, to recognize investment losses for funding purpose. + References No definition available. + Details
Name: | prim_MultiemployerPlansInvestmentLossesSmoothingPeriodBeforeAmendment
Namespace Prefix: | prim_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the temporary surcharge as a percentage of total contributions imposed during the period. + References No definition available. + Details
Name: | prim_MultiemployerPlansPercentageOfTemporarySurcharge
Namespace Prefix: | prim_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents selling, general and administrative expenses related to the 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 No definition available. + Details
Name: | prim_MultiemployerPlansSellingGneralAndAdministrationExpense
Namespace Prefix: | prim_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_MultiemployerPlansLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of contributions made to the multiemployer plan by all employers who participate in the plan. 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 7 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=14450570&loc=SL14450678-114947 + Details
Name: | us-gaap_MultiemployerPlansPlanContributions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of the obligation recognized by withdrawing from 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 No definition available. + Details
Name: | us-gaap_MultiemployerPlansWithdrawalObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant