Contracts in Process (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Contracts Receivable [Abstract]
Unbilled contract receivables, gross	$ 2,020	$ 2,120
Unliquidated progress payments	(827)	(892)
Unbilled contract receivables, net	1,193	1,228
Inventoried contract costs, gross	1,065	975
Unliquidated progress payments	(203)	(122)
Inventoried contract costs, net	862	853
Total contracts in process	$ 2,055	2,081
Percentage of unbilled contract receivables, net billed and collected within one year	95.00%
Contracts Receivable [Line Items]
Percentage of incurred costs billed	80.00%
Summary of Inventory for Long Term Contracts or Programs [Roll Forward]
Amounts included in inventoried contract costs at beginning of the year	$ 137	114	$ 121
Contract costs incurred [Abstract]:
IRAD and B&P	308	284	270
Other G&A	839	822	804
Total	1,147	1,106	1,074
Amounts charged to cost of sales	(1,111)	(1,083)	(1,081)
Amounts included in inventoried contract costs at end of the year	173	137	114
Operating Expenses [Abstract]
Selling, general and administrative expenses	223	261	297
Research and development expenses	54	52	63
Total	$ 277	$ 313	$ 360
Maximum [Member]
Contracts Receivable [Line Items]
Number of years for billed and collected, unbilled contract receivables	1 year