Revenue Contract Balances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue [Abstract]
Contract with Customer, Liability	$ 117	$ 109
Contract with Customer, Liability, Revenue Recognized	13	36
Financing Receivable, before Allowance for Credit Loss, Noncurrent	$ 1,351	$ 1,423	$ 1,490	$ 0