New Accounting Pronouncements New Accounting Pronouncements (Details) - USD ($)
$ in Millions
Sep. 30, 2017
Jan. 01, 2017
New Accounting Pronouncements [Abstract]    
Effect of early adoption of income tax consequences of intra-entity transfer of assets other than inventory $ 384 [1] $ 384
[1] Represents a cumulative-effect adjustment to retained earnings upon our adoption of a new accounting standards update on the income tax consequences of intra-entity transfers of assets other than inventory which was effective January 1, 2017. See Note 8 for further information.