Other Current Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Other Assets [Abstract]
Derivative Asset	$ 624		$ 624		$ 636
Deferred receivables consideration	447		447		379
Receivables from Customers	593		593		450
Financing Receivable, after Allowance for Credit Loss	514		514		424
Premiums Receivable, Net	68		68		35
Prepaid Expense, Current	286		286		184
Tax receivables	462		462		379
Other Receivables	344		344		323
Other current assets	249		249		223
Total other current assets	3,587		3,587		3,033
Financing Receivable, Allowance for Credit Loss	4		4		3
Interest on financing receivables	6	$ 5	14	$ 12
Asset Impairment Charges	35		44
Reinsurance Recoverables	$ 82		$ 82		$ 84