Revenues and Segment Information, Contract Balances (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Receivables from contracts with customers, included in receivables, net
Increase		$ (3,400)
Contract liabilities, included in accrued expenses
Beginning balance	$ 55
Increase	49
Ending balance	104
Contract Balances (Textual)
Revenue recognized that was included in contract liabilities as of prior year end	37	$ 52
Receivables from Contracts with Customers [Member]
Receivables from contracts with customers, included in receivables, net
Beginning balance	3,642
Increase	1,059
Ending balance	$ 4,701