Revenues and Segment Information, Contract Balances (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Receivables from contracts with customers, included in receivables, net
Increase (Decrease)		$ (4,100)
Contract liabilities, included in accrued expenses
Beginning balance	$ 55
Increase (Decrease)	(15)
Ending balance	40
Contract Balances (Textual)
Revenue recognized that was included in contract liabilities as of prior year end	40	$ 52
Receivables from Contracts with Customers [Member]
Receivables from contracts with customers, included in receivables, net
Beginning balance	3,642
Increase (Decrease)	2,023
Ending balance	$ 5,665