Operating Segments and Geographic Data - Segment Assets (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Segment Assets
Assets	$ 223,403	$ 237,428
Goodwill	4,416	4,463
United States
Segment Assets
Assets	61,845	64,598
International
Segment Assets
Assets	157,142	168,367
Operating Segments
Segment Assets
Assets	213,210	228,189
Operating Segments | Upstream
Segment Assets
Assets	174,360	186,037
Goodwill	4,416	4,463
Operating Segments | Upstream | United States
Segment Assets
Assets	33,869	35,926
Operating Segments | Upstream | International
Segment Assets
Assets	136,075	145,648
Operating Segments | Downstream
Segment Assets
Assets	38,850	42,152
Operating Segments | Downstream | United States
Segment Assets
Assets	23,001	25,197
Operating Segments | Downstream | International
Segment Assets
Assets	15,849	16,955
All Other
Segment Assets
Assets	10,193	9,239
All Other | United States
Segment Assets
Assets	4,975	3,475
All Other | International
Segment Assets
Assets	$ 5,218	$ 5,764