Subsequent Events (Details) (Discontinued Operations [Member], Pioneer Alaska [Member], USD $) In Millions, unless otherwise specified	May 05, 2014
Discontinued Operations [Member] \| Pioneer Alaska [Member]
Subsequent Event [Line Items]
Significant Acquisition and Disposal, Acquisition Costs or Sales Proceeds	$ 300

The value of all consideration given or received by the Entity in the significant acquisition or disposal.

No definition available.

Name:	us-gaap_SignificantAcquisitionsAndDisposalsAcquisitionCostsOrSaleProceeds
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant