XML 47 R36.htm IDEA: XBRL DOCUMENT v3.25.1

Note L - Subsequent Event (Details Textual) - Vendor in Housewares/Small Appliances Segment [Member]	3 Months Ended
	Mar. 30, 2025 USD ($)
Payments for Deposits	$ 2,701,000
Deposits, Impairment	$ 0

X

- Definition

Represents the amount of impairment on deposits.

+ References

No definition available.

+ Details

Name:	npk_DepositsImpairment
Namespace Prefix:	npk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The amount of cash paid for deposits on goods and services during the period; excludes time deposits and deposits with other institutions, which pertain to financial service entities.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-17

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 17
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-17

+ Details

Name:	us-gaap_PaymentsForDeposits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	srt_CounterpartyNameAxis=npk_VendorInHousewaressmallAppliancesSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: