Letters of credit outstanding relate to joint venture operations.

No definition available.

Name:	kbr_LettersOfCreditOutstandingRelateToJointVentureOperations
Namespace Prefix:	kbr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

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Namespace Prefix:	us-gaap_
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Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Data Type:	xbrli:monetaryItemType
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- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Debt and Other Credit Facilities (Letters of Credit, Surety Bonds and Guarantees) (Details) - USD ($)	Oct. 03, 2025	Apr. 25, 2018
Letters of Credit Surety Bonds and Bank Guarantees
Debt Instrument [Line Items]
Letters of credit outstanding relate to joint venture operations	$ 88,000,000
Revolver \| Revolver
Debt Instrument [Line Items]
Revolving credit facility		$ 1,000,000,000
Long-term line of credit	395,000,000
Letters of credit outstanding	14,000,000
Remaining borrowing capacity	814,000,000
Revolver \| Committed Line of Credit \| Revolver
Debt Instrument [Line Items]
Revolving credit facility	1,000,000,000
Revolver \| Uncommitted Line of Credit \| Revolver
Debt Instrument [Line Items]
Revolving credit facility	489,000,000
Letter of Credit \| Uncommitted Line of Credit \| Revolver
Debt Instrument [Line Items]
Letters of credit outstanding	$ 266,000,000