Accounts Receivable, Net (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Accounts receivable, gross	$ 1,534	$ 1,359
Allowance for expected credit losses	(33)	(33)
Accounts receivable, net	1,501	1,326
US Government [Member]
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Accounts receivable, gross	956	1,030
International and Other Customers [Member]
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Accounts receivable, gross	$ 578	$ 329