Accounts Receivable, Net (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Accounts Receivable, Net [Abstract]
Total accounts receivable	$ 3,362	$ 2,900
Allowance for doubtful accounts	(63)	(59)
Total accounts receivable, net	3,299	2,841
US Government
Accounts Receivable, Net [Abstract]
Billed	444	506
Unbilled	8,878	7,699
Progress and performance-based payments received	(7,123)	(6,140)
Total accounts receivable	2,199	2,065
Other Customers
Accounts Receivable, Net [Abstract]
Billed	238	223
Unbilled	4,747	3,713
Progress and performance-based payments received	(3,822)	(3,101)
Total accounts receivable	$ 1,163	$ 835