Subsequent Events (Unaudited) (Details) (Subsequent Event [Member], USD $) In Billions, unless otherwise specified	3 Months Ended
	Jun. 30, 2014
Encana Corporation [Member]
Subsequent Event [Line Items]
Sale and Purchase Transaction, Announcement Date	May 07, 2014
Payments for (Proceeds from) Productive Assets	$ 3.1
Disposal and/or Acquisition Date	Apr. 01, 2014
Threshhold for Determining Accounting Treatment for Oil and Gas Dispositions	25.00%
Apache Corporation [Member]
Subsequent Event [Line Items]
Sale and Purchase Transaction, Announcement Date	May 08, 2014
Payments for (Proceeds from) Productive Assets	$ 1.4
Exploration Leases	11
Disposal and/or Acquisition Date	May 01, 2014
Eagle Ford [Member] | Maximum [Member] | Encana Corporation [Member]
Subsequent Event [Line Items]
Threshhold for Determining Accounting Treatment for Oil and Gas Dispositions	25.00%