Revenues - Receivables (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Receivables for Product and Services in Accounts Receivable, Net	$ 793	$ 1,156
Equipment Receivables	42	85
Contract Assets	1	3
Contract Liabilities	29	$ 12
Contract with Customer, Liability, Revenue Recognized	$ 8