BASIS OF PRESENTATION (Details)	3 Months Ended
Apr. 01, 2012 W	Apr. 03, 2011 W
Number of weeks in fiscal quarters	13	13
Maximum
Number of weeks in fiscal year	53
Number of weeks in fiscal quarters	14
Minimum
Number of weeks in fiscal year	52
Number of weeks in fiscal quarters	13

Disclosure of the number of weeks included in the entity's fiscal quarters.

No definition available.

Name:	pwer_NumberOfWeeksInFiscalQuarters
Namespace Prefix:	pwer_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration