INFORMATION ON BUSINESS SEGMENTS - Total Assets For Each Business Segment (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total assets	$ 45,495	$ 46,620
Business segments
Segment Reporting Information [Line Items]
Total assets	37,625	35,822
Business segments | Aeronautics
Segment Reporting Information [Line Items]
Total assets	8,746	7,713
Business segments | Missiles and Fire Control
Segment Reporting Information [Line Items]
Total assets	4,865	4,577
Business segments | Rotary and Mission Systems
Segment Reporting Information [Line Items]
Total assets	18,545	18,292
Business segments | Space
Segment Reporting Information [Line Items]
Total assets	5,469	5,240
Corporate
Segment Reporting Information [Line Items]
Total assets	$ 7,870	$ 10,798