Pending Acquisition Pending Acquisition (Details) - 3 months ended Sep. 30, 2016 shares in Millions, $ in Millions	USD ($) shares	a	USD ($)
Business Acquisition [Line Items]
Oil and gas producing wells, gross	3,000	30
Payments to Acquire Businesses, Gross	$ 915
Stock Issued During Period, Shares, Acquisitions | shares	9.4
Stock Issued During Period, Value, Acquisitions	$ 590
Other Payments to Acquire Businesses	100
Bridge Loan			$ 600
Loan Processing Fee	9
Line of Credit Facility, Commitment Fee Amount	$ 6
Business Acquisition, Transaction Costs			10
Oil and Gas Properties [Member]
Business Acquisition [Line Items]
Gas and Oil Area, Developed, Gross | a		57,000
Noble acres transferred to PDC [Member]
Business Acquisition [Line Items]
Gas and Oil Area, Developed, Gross | a		13,500
PDC acres transferred to Noble [Member]
Business Acquisition [Line Items]
Gas and Oil Area, Developed, Gross | a		11,700
Revolving Credit Facility
Business Acquisition [Line Items]
Line of credit facility, increase in commitments			$ 250