Maximum lending capacity under the terms noted per the related party credit facility.

No definition available.

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Namespace Prefix:	nl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Rent and related ancillary service cost.

+ References

No definition available.

+ Details

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- Definition

Face (par) amount of debt instrument at time of issuance.

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of operating interest income, including, but not limited to, amortization and accretion of premiums and discounts on securities.

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- 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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- Definition

Percentage added to reference rate used to compute variable rate on loan receivable.

+ References

No definition available.

+ Details

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- Definition

Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Excludes Selling, General and Administrative Expense.

+ References

No definition available.

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- Definition

Amount, after allowance for credit loss, of receivable classified as other and noncurrent.

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- 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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Related party transactions - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Feb. 29, 2024
Related Party Transaction
Note receivable from affiliate	$ 9,300	$ 10,600
Contran \| Kronos
Related Party Transaction
Rent and related ancillary service	700	600	$ 500
Related Party \| Contran \| Unsecured term loan \| Kronos
Related Party Transaction
Unsecured term loan				$ 53,700
Related Party \| Tall Pines
Related Party Transaction
Expense transaction with affiliate	21,400	20,700	18,200
Related Party \| Intercorporate Services Agreement Fees \| Contran
Related Party Transaction
Expense transaction with affiliate	32,200	30,800	33,500
Related Party \| Insurance Premiums \| Tall Pines and EWI
Related Party Transaction
Expense transaction with affiliate	29,100	28,400	24,300
Related Party \| Combined Information Technology Data Recovery Program \| Contran \| Kronos
Related Party Transaction
Expense transaction with affiliate	400	400	300
NLKW Holding, LLC \| Valhi \| Valhi Credit Facility
Related Party Transaction
Outstanding borrowings	500	500
CompX \| Valhi Inc \| Unsecured Revolving Promissory Note Receivable
Related Party Transaction
Maximum loan amount	$ 25,000
Interest rate on loans repayment	1.00%
CompX \| Related Party \| Unsecured Revolving Promissory Note Receivable \| Valhi
Related Party Transaction
Note receivable from affiliate	$ 9,300	10,600
Interest income including unused commitment fees	$ 1,000	$ 1,200	$ 1,000