Summary of Significant Accounting Policies Backlog and Contract Assets and Liabilities (Details 6) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Backlog, Awards, and Related Adjustments [Line Items]
Revenue, Remaining Performance Obligation, Amount		$ 95,700
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Explanation		Of our December 31, 2025 backlog, we expect to recognize approximately 35 percent as revenue over the next 12 months and 60 percent as revenue over the next 24 months, with the remainder to be recognized thereafter.
Change in Contract with Customer, Asset and Liability [Abstract]
Contract with Customer, Liability, Revenue Recognized		$ 3,300	$ 3,600	$ 3,100
Increase (decrease) in Contract with Customer, Asset, Current		$ 636
Percent increase (decrease) in Unbilled Receivables		11.00%
Advance payments and billings in excess of costs incurred		$ (4,086)	(4,070)
Decrease (increase) in Contract with Customer, Liability, Current		$ 16
Percent decrease (increase) in Contract with Customer, Liability, Current		0.00%
Net contract assets		$ 2,458	$ 1,838
Amount of increase (decrease) in net contract assets (liabilities)		$ 620
Percent increase (decrease) in net contract assets (liabilities)		34.00%
Contract with Customer, Asset, Explanation of Change		Changes in the company’s contract assets and liabilities primarily result from timing differences between revenue recognition and customer billings and/or payments. Net contract assets as of December 31, 2025 increased 34 percent from the prior year, primarily due to increases in unbilled receivables driven by the timing of deliveries and achievement of billing milestones on certain programs at Defense Systems.
Increase (decrease) in Contract with Customer, Asset, Current		$ 636
Defense Systems | Training services business [Member]
Backlog, Awards, and Related Adjustments [Line Items]
Backlog Reduction due to Divestiture	$ 150
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-12-31
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Percentage		35.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period		12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Percentage		60.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period		24 months