Significant Accounting Policies - Additional Information (Detail)	3 Months Ended			12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares	Jun. 24, 2018 USD ($) $ / shares	Mar. 26, 2017 USD ($) $ / shares	Dec. 31, 2019 USD ($) program contract $ / shares	Dec. 31, 2018 USD ($) $ / shares	Dec. 31, 2017 USD ($) $ / shares
Significant Accounting Policies [Line Items]
Number of contract types | contract				3
Ending backlog				$ 144,000,000,000.0
Performance obligation satisfied in previous period				2,200,000,000	$ 2,000,000,000.0	$ 1,800,000,000
Severance and restructuring charges				0	96,000,000	0
Independent research and development costs charged to cost of sales				$ 1,300,000,000	1,300,000,000	1,200,000,000
Weighted average remaining contractual life, vested				3 years
Financing receivable, significant sales				$ 387,000,000	532,000,000
Gain (loss) on sale of accounts receivable				0	0
Depreciation				794,000,000	759,000,000	760,000,000
Capitalized internal-use software, net	$ 447,000,000			511,000,000	447,000,000
Capitalized internal-use software accumulated amortization	2,100,000,000			2,200,000,000	2,100,000,000
Goodwill	10,769,000,000			$ 10,604,000,000	10,769,000,000	10,807,000,000
Time period environmental costs and recovery of environmental costs are projected over				20 years
Fair value of trading securities	1,300,000,000			$ 1,800,000,000	1,300,000,000
Net gains (losses) on marketable securities				233,000,000	(67,000,000)	150,000,000
Total equity method investments	1,200,000,000			1,200,000,000	1,200,000,000
Net earnings from equity method investments				154,000,000	119,000,000	207,000,000
Contracts Accounted for under Percentage of Completion
Significant Accounting Policies [Line Items]
Increase in operating profit due to profit rate adjustments				1,900,000,000	$ 1,900,000,000	1,600,000,000
Increase in net earnings due to profit rate adjustments				$ 1,500,000,000		$ 1,100,000,000
Increase in diluted earnings per common share due to profit rate (in dollars per share) | $ / shares				$ 5.29	$ 5.23	$ 3.79
Minimum
Significant Accounting Policies [Line Items]
Acquired finite-lived intangible assets are amortized				3 years
Minimum | Customer programs
Significant Accounting Policies [Line Items]
Acquired finite-lived intangible assets are amortized				9 years
Maximum
Significant Accounting Policies [Line Items]
Acquired finite-lived intangible assets are amortized				20 years
Maximum | Customer programs
Significant Accounting Policies [Line Items]
Acquired finite-lived intangible assets are amortized				20 years
Designated as hedges | Interest rate swaps
Significant Accounting Policies [Line Items]
Aggregate notional amount of derivatives	1,300,000,000			$ 750,000,000	$ 1,300,000,000
Designated as hedges | Foreign currency contracts
Significant Accounting Policies [Line Items]
Aggregate notional amount of derivatives	3,500,000,000			3,800,000,000	3,500,000,000
RMS
Significant Accounting Policies [Line Items]
Severance and restructuring charges		$ 96,000,000		60,000,000
Severance and restructuring charges, net of tax		$ 76,000,000		$ 47,000,000
Severance and restructuring charges (in dollars per share) | $ / shares		$ 0.26		$ 0.17
Goodwill	6,751,000,000			$ 6,758,000,000	6,751,000,000	$ 6,784,000,000
Space
Significant Accounting Policies [Line Items]
Number of commercial satellite programs with performance issues | program				2
Goodwill	1,585,000,000			$ 1,586,000,000	1,585,000,000	1,587,000,000
Net earnings from equity method investments				$ 145,000,000	210,000,000	205,000,000
Buildings | Minimum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated life				10 years
Buildings | Maximum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated life				40 years
Machinery and equipment | Minimum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated life				5 years
Machinery and equipment | Maximum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated life				15 years
Capitalized Software
Significant Accounting Policies [Line Items]
Capitalized internal-use software amortization				$ 111,000,000	106,000,000	123,000,000
Capitalized Software | Minimum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated life				2 years
Capitalized Software | Maximum
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated life				6 years
EADGE-T
Significant Accounting Policies [Line Items]
Contract loss incurred, gross						120,000,000
Contract loss incurred, after tax						$ 74,000,000
Contract loss incurred, after tax (in dollars per share) | $ / shares						$ 0.25
Commercial satellite cumulative losses on development				$ 260,000,000		$ 260,000,000
LM2100
Significant Accounting Policies [Line Items]
Commercial satellite cumulative losses on development				410,000,000
Warrior Capability Sustainment Program
Significant Accounting Policies [Line Items]
Contract loss incurred, gross					85,000,000
Contract loss incurred, after tax					$ 64,000,000
Contract loss incurred, after tax (in dollars per share) | $ / shares					$ 0.22
Commercial satellite cumulative losses on development				$ 140,000,000
AMMROC
Significant Accounting Policies [Line Items]
Equity method investee impairment	110,000,000		$ 64,000,000
Equity method investee impairment, net of tax	$ 83,000,000		$ 40,000,000
Equity method investee impairment (in dollars per share) | $ / shares	$ 0.29		$ 0.14
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage				39.00%
Expected time of satisfaction				12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, percentage				26.00%
Expected time of satisfaction				12 months
Operations Consolidation [Member]
Significant Accounting Policies [Line Items]
Commercial satellite cumulative losses on development				$ 205,000,000