Goodwill and Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1]	$ 3,874	$ 4,210
Accumulated Amortization		(1,896)	(2,093)
Net Carrying Amount		1,978	2,117
Contract and Program Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1],[2]	3,239	3,399
Accumulated Amortization	[2]	(1,547)	(1,600)
Net Carrying Amount		1,692	1,799
Tradenames and Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1]	501	516
Accumulated Amortization		(238)	(229)
Net Carrying Amount		263	287
Technology and Software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1]	70	134
Accumulated Amortization		(48)	(106)
Net Carrying Amount		22	28
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	[1]	64	161
Accumulated Amortization		(63)	(158)
Net Carrying Amount		$ 1	$ 3

[1] Changes in gross carrying amounts consisted primarily of adjustments for write-offs of fully amortized intangible assets, acquired intangible assets and foreign currency translation.

[2] Consisted of acquired backlog and probable follow-on work and associated customer relationships.