Liabilities, Commitments and Contingencies - Narrative (Details) $ in Millions	3 Months Ended			12 Months Ended
	Mar. 31, 2026 USD ($) aircraft lot	Mar. 31, 2025 USD ($)	Sep. 30, 2018 USD ($) aircraft	Dec. 31, 2025 USD ($)	Dec. 31, 2018 USD ($) aircraft simulator	Jun. 30, 2025 aircraft	Dec. 31, 2011 tanker aircraft lot
Commitments And Contingencies [Line Items]
Environmental loss contingency, operation and maintenance period, maximum	30 years
Loss contingency, range of possible loss, portion not accrued	$ 1,171			$ 1,171
Contingent liabilities on outstanding letters of credit agreements and surety bonds	3,340			3,295
Supplier finance program, obligation	1,828			1,994
Increase (decrease) in earnings from operations due to change in accounting estimate	(31)	$ (151)
Number of annual production lot | lot							13
VC-25B
Commitments And Contingencies [Line Items]
Contract value	$ 4,000
Number of commercial aircraft | aircraft	2
Increase (decrease) in earnings from operations due to change in accounting estimate				(60)
KC-46A Tanker
Commitments And Contingencies [Line Items]
Contract value	$ 32,000
Increase (decrease) in earnings from operations due to change in accounting estimate				(714)
Number of generation aerial refueling tanker | tanker							4
Number of aircraft | aircraft	169						179
Number of low rate initial production lot | lot	12
KC-46A Tanker | Capitalized Precontract Costs
Commitments And Contingencies [Line Items]
Capitalized precontract costs	$ 69
KC-46A Tanker | Potential Termination Liabilities
Commitments And Contingencies [Line Items]
Capitalized precontract costs	$ 74
MQ-25
Commitments And Contingencies [Line Items]
Contract value			$ 890
Increase (decrease) in earnings from operations due to change in accounting estimate			$ (291)
Number of aircraft | aircraft			7
T-7A EMD
Commitments And Contingencies [Line Items]
Contract value					$ 860
Number of aircraft | aircraft	5				5	4
Number of simulator | simulator					7
T-7A Production
Commitments And Contingencies [Line Items]
Increase (decrease) in earnings from operations due to change in accounting estimate					$ (400)
Number of aircraft | aircraft						342
T-7A Production | Capitalized Precontract Costs
Commitments And Contingencies [Line Items]
Capitalized precontract costs	$ 400
T-7A Production | Potential Termination Liabilities
Commitments And Contingencies [Line Items]
Capitalized precontract costs	1,002
Commercial Crew | Capitalized Precontract Costs
Commitments And Contingencies [Line Items]
Capitalized precontract costs	554
Commercial Crew | Potential Termination Liabilities
Commitments And Contingencies [Line Items]
Capitalized precontract costs	$ 28
Minimum | Supplier Finance Program, Majority of Amounts Payable
Commitments And Contingencies [Line Items]
Supplier finance program, payment timing, period	30 days
Maximum | Supplier Finance Program, Majority of Amounts Payable
Commitments And Contingencies [Line Items]
Supplier finance program, payment timing, period	90 days
Commercial Aircraft Commitments | Total Contractual Trade-In Commitment
Commitments And Contingencies [Line Items]
Other commitment	$ 1,228			1,267
Commercial Aircraft Commitments | Net Amounts Payable to Customers Related to Probable Contractual Trade-In Commitments
Commitments And Contingencies [Line Items]
Other commitment	61			67
Commercial Aircraft Commitments | Fair Value of Trade in Value of Aircraft
Commitments And Contingencies [Line Items]
Other commitment	56			61
Financing Commitment
Commitments And Contingencies [Line Items]
Other commitment	17,730			$ 15,229
Financing Commitment | External Credit Rating, Non Investment Grade
Commitments And Contingencies [Line Items]
Other commitment	12,590
Joint Venture
Commitments And Contingencies [Line Items]
Other commitment	$ 281
Other commitment, period	12 years
Contingent on Customer Negotiations
Commitments And Contingencies [Line Items]
737 MAX customer concessions and other considerations liability	$ 89