Acquisitions Acquisitions Asset (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended			1 Months Ended	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 31, 2014	Dec. 31, 2014
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired	$ 21	$ 74	$ 1,033
Oklahoma Resource Basin [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired				80
SCOOP [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired					$ 60