Related-Party Transactions Related-Party Transactions (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012
Related Party Transactions [Abstract]
Related Party Transaction, Cash (Paid) Received for Income Taxes, Net	$ (69)	$ 210

The amount of cash received during the current period from affiliates for refunds for the overpayment of taxes on income, net of any amounts paid during the current period.

No definition available.

Name:	pcorp_RelatedPartyTransactionCashReceivedForIncomeTaxesNet
Namespace Prefix:	pcorp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration