Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014
Fair Value Measurements [Abstract]
Prepaid and other current assets and in other assets	$ 10
Fair value of barter credits recorded in other assets	$ 187

Fair value of prepaid expenses and other current assets related to the barter credit transactions.

No definition available.

Name:	prmw_FairValueOfBarterCreditsRecordedInPrepaidExpensesAndOtherCurrentAssets
Namespace Prefix:	prmw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant