Acquisition and Divestitures Acquisition and Divestitures (Details) - USD ($) $ in Millions			3 Months Ended			6 Months Ended
		Jan. 01, 2017	Jun. 30, 2017	Jun. 30, 2016		Jun. 30, 2017	Jun. 30, 2016		Dec. 31, 2016
Acquisition and Divestitures
Goodwill			$ 127			$ 127			$ 117
Business Acquisition, Revenue				$ 348			$ 692
Business Acquisition, Net Earnings				90			177
Payments for (Proceeds from) Other Investing Activities	[1]					(28)	0
Gain (Loss) on Disposition of Property Plant Equipment			25	$ 0	[2]	25	$ (1)	[2]
North Dakota Gathering and Processing Assets [Member]
Acquisition and Divestitures
Business Combination, Consideration Transferred		$ 705
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment						31
Goodwill, Purchase Accounting Adjustments						4
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Intangibles						(32)
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory						(3)
Inventory			2			2
Property, plant and equipment			571			571
Intangibles	[3]		122			122
Goodwill			10			10
Total purchase price			705			$ 705
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life						10 years 7 months 6 days
Amortization of Intangible Assets			3			$ 7
Business Acquisition, Revenue			97			196
Business Acquisition, Net Earnings			$ 13			$ 26

[1] (a)Adjusted to include the historical results of the Predecessors. See Note 1 for further discussion.

[2] Adjusted to include the historical results of the Predecessors. See Note 1 for further discussion.

[3] The intangibles consist of customer contracts with a weighted average amortization period of 10.6 years. Amortization of intangible assets for the three and six months ended June 30, 2017 was $3 million and $7 million, respectively.