COMPONENTS OF NET PERIODIC PENSION COST (Details Textuals) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2012	Apr. 30, 2011
Compensation and Retirement Disclosure [Abstract]
Net periodic pension benefit cost included in discontinued operations	$ 185	$ 177	$ 552	$ 536

The amount of net periodic pension benefit cost included in discontinued operations.

No definition available.

Name:	pll_NetPeriodicPensionBenefitCostDiscontinuedOperations
Namespace Prefix:	pll_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration