Accounts Receivable, Net - Accounts Receivable Sales Arrangements (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Accounts Receivable Sales Arrangements [Abstract]
Uncollected accounts receivable sold and derecognized		$ 94		$ 94		$ 131
Accounts Receivable
Accounts Receivable Sales Arrangements [Abstract]
Accounts receivable sales	[1]	67	$ 66	265	$ 297
Loss on sales of accounts receivable		$ 1	$ 1	$ 2	$ 2

[1] Customers may also enter into structured-payable arrangements that require us to sell our receivables from that customer to a third-party financial institution, which then makes payments to us to settle the customer's receivable. In these instances, we ensure the sale of the receivables are bankruptcy-remote and the payment made to us is without recourse. The activity associated with these arrangements is not reflected in this disclosure, as payments under these arrangements have not been material and these are customer directed arrangements.