Other Current Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Other Assets [Abstract]
Derivative Asset	$ 963		$ 963		$ 449
Deferred receivables consideration	386		386		307
Receivables from Customers	359		359		477
Financing Receivable, Net	721		721		413
Premiums Receivable, Net	42		42		129
Prepaid Expense, Current	255		255		232
Tax receivables	350		350		425
Other Receivables	310		310		371
Other current assets	256		256		372
Total other current assets	3,642		3,642		3,175
Financing Receivable, Allowance for Credit Losses	7		7		6
Interest on financing receivables	5	$ 5	12	$ 12
Asset Impairment Charges	21	$ 17	21	$ 18
Reinsurance Recoverables	$ 62		$ 62		$ 91