Basis of Presentation and Significant Accounting Policies (Details) - USD ($) $ in Millions			9 Months Ended
		Jan. 01, 2019	Sep. 30, 2019
Basis of Presentation and Significant Accounting Policies (Textual)
Recognition of ROU assets and lease liabilities for operating leases	[1]		$ 1,673
Topic 842 [Member]
Basis of Presentation and Significant Accounting Policies (Textual)
Recognition of ROU assets and lease liabilities for operating leases		$ 1,300
Topic 842 [Member] | MVP Terminal [Member]
Basis of Presentation and Significant Accounting Policies (Textual)
Derecognition of existing assets under construction related to build-to-suit lease arrangement		$ 539

[1] Includes noncash activity of $1.3 billion for ROU assets for operating leases recorded on January 1, 2019 upon adoption of Topic 842.