Revenues and Segment Information, Contract Balances (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Contract liabilities, included in accrued expenses
Beginning balance	$ 55
Decrease	(36)
Ending balance	19
Contract Balances (Textual)
Revenue recognized that was included in contract liabilities as of prior period end	52
Receivables from Contracts with Customers [Member]
Receivables from contracts with customers, included in receivables, net
Beginning balance	5,610
Decrease	(2,645)
Ending balance	$ 2,965