Information on Business Segments - Narrative (Detail) $ in Millions	12 Months Ended
Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017
Segment Reporting Information [Line Items]
Number of business segments \| segment	4
Equity method investments	$ 1,200	$ 1,200
Net Sales \| Product Concentration Risk \| F-35 Program \| Aeronautics
Segment Reporting Information [Line Items]
Net sales for the F-35 program representing total consolidated net sales (as a percent)	27.00%	27.00%	26.00%
United Launch Alliance
Segment Reporting Information [Line Items]
Percentage of ownership interest in affiliated entity	50.00%
Equity method investments	$ 709	$ 687

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 25
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8813-108599

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_EquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant