Segment Information Geographic Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	$ 63,500	$ 65,034	$ 65,699
Revenues	136,341	127,144	155,900
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	44,271	45,360	46,434
Revenues	87,012	82,535	98,729
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	5,773	5,111	4,842
Revenues	11,153	8,711	10,855
Germany
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	2,708	3,197	3,225
Revenues	6,237	6,526	7,930
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	1,383	1,401	1,541
Revenues	7,607	6,110	8,899
MEXICO
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	3,903	3,669	2,909
Revenues	1,440	1,030	1,451
All Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-Lived Assets	5,462	6,296	6,748
Revenues	$ 22,892	$ 22,232	$ 28,036