XML 32 R50.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Nature of Business (Details) | 12 Months Ended | 1 Months Ended
--- | --- | ---
Dec. 31, 2012 item | Mar. 31, 2012 Sprint
Asset purchase agreement |  |
Number of acquisitions | 4 |
Period for which the acquiree name is allowed to be used |  | 3 years

X
- Definition Represents the number of business acquisitions made by the entity. + References No definition available. + Details
Name: | prim_BusinessAcquisitionNumberOfAcquisitions
Namespace Prefix: | prim_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the period for which the entity is allowed to use the acquiree name as per the purchase agreement. + References No definition available. + Details
Name: | prim_BusinessAcquisitionPeriodForWhichAcquireeNameIsAllowedToBeUsed
Namespace Prefix: | prim_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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