XML 71 R61.htm IDEA: XBRL DOCUMENT
v3.25.3

Stockholders' Equity Transactions (Details) - USD ($) $ / shares in Units, $ in Millions |  | 1 Months Ended | 3 Months Ended | 9 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Sep. 19, 2024 | Oct. 30, 2025 | Mar. 20, 2025 | Dec. 19, 2024 | Sep. 30, 2025 | Jun. 30, 2025 | Mar. 31, 2025 | Dec. 31, 2024 | Sep. 30, 2024 | Mar. 31, 2025 | Nov. 30, 2024 | Dec. 31, 2017 | Sep. 16, 2014
Equity |  |  |  |  |  |  |  |  |  |  |  |  |
Cash dividend declared (in dollars per share) |  |  |  |  | $ 0.14 |  |  |  | $ 0.125 |  |  |  |
Authorized to be repurchased |  |  |  |  |  |  |  |  |  |  |  |  | $ 2
Authorized to be repurchased (in shares) |  |  |  |  |  |  |  |  |  |  |  |  | 38,800,000
Authorized additional number of shares |  |  |  |  |  |  |  |  |  |  | 1,000,000 | 1,000,000 |
Treasury stock shares acquired | 193,252 |  | 745,000 | 282,647 |  |  | 745,000 | 282,647 | 193,252 | 1,220,899 |  |  |
Number of share available can be repurchased | 1,387,388 |  | 359,741 | 1,104,741 | 359,741 |  | 359,741 |  |  | 359,741 |  |  |
Weighted average cost per share | $ 37.67 |  | $ 25.22 | $ 37.95 |  |  | $ 25.22 | $ 37.95 | $ 37.67 | $ 30.14 |  |  |
Exercised |  |  |  |  | 18,000 |  |  |  |  |  |  |  |
O 2025 Q1 dividends |  |  |  |  |  |  |  |  |  |  |  |  |
Equity |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends payable date declared |  |  |  |  |  |  |  |  | Aug. 22, 2024 |  |  |  |
Dividends payable date of record |  |  |  |  |  |  |  |  | Sep. 12, 2024 |  |  |  |
Dividends payable date to be paid |  |  |  |  |  |  |  |  | Oct. 03, 2024 |  |  |  |
Cash dividend declared (in dollars per share) |  |  |  |  |  |  |  |  | $ 0.125 |  |  |  |
O 2025 Q2 dividends |  |  |  |  |  |  |  |  |  |  |  |  |
Equity |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends payable date declared |  |  |  |  |  |  |  | Nov. 01, 2024 |  |  |  |  |
Dividends payable date of record |  |  |  |  |  |  |  | Dec. 12, 2024 |  |  |  |  |
Dividends payable date to be paid |  |  |  |  |  |  |  | Jan. 03, 2025 |  |  |  |  |
Cash dividend declared (in dollars per share) |  |  |  |  |  |  |  | $ 0.125 |  |  |  |  |
O 2025 Q3 Dividends |  |  |  |  |  |  |  |  |  |  |  |  |
Equity |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends payable date declared |  |  |  |  |  |  | Jan. 30, 2025 |  |  |  |  |  |
Dividends payable date of record |  |  |  |  |  |  | Mar. 12, 2025 |  |  |  |  |  |
Dividends payable date to be paid |  |  |  |  |  |  | Apr. 03, 2025 |  |  |  |  |  |
Cash dividend declared (in dollars per share) |  |  |  |  |  |  | $ 0.125 |  |  |  |  |  |
O 2025 Q4 Dividends |  |  |  |  |  |  |  |  |  |  |  |  |
Equity |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends payable date declared |  |  |  |  |  | May 02, 2025 |  |  |  |  |  |  |
Dividends payable date of record |  |  |  |  |  | Jun. 12, 2025 |  |  |  |  |  |  |
Dividends payable date to be paid |  |  |  |  |  | Jul. 03, 2025 |  |  |  |  |  |  |
Cash dividend declared (in dollars per share) |  |  |  |  |  | $ 0.14 |  |  |  |  |  |  |
O 2026 Q1 Dividends |  |  |  |  |  |  |  |  |  |  |  |  |
Equity |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends payable date declared |  |  |  |  | Aug. 21, 2025 |  |  |  |  |  |  |  |
Dividends payable date of record |  |  |  |  | Sep. 12, 2025 |  |  |  |  |  |  |  |
Dividends payable date to be paid |  |  |  |  | Oct. 03, 2025 |  |  |  |  |  |  |  |
Cash dividend declared (in dollars per share) |  |  |  |  | $ 0.14 |  |  |  |  |  |  |  |
O 2026 Q2 Dividends | Subsequent Events |  |  |  |  |  |  |  |  |  |  |  |  |
Equity |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends payable date declared |  | Oct. 30, 2025 |  |  |  |  |  |  |  |  |  |  |
Dividends payable date of record |  | Dec. 12, 2025 |  |  |  |  |  |  |  |  |  |  |
Dividends payable date to be paid |  | Jan. 02, 2026 |  |  |  |  |  |  |  |  |  |  |
Cash dividend declared (in dollars per share) |  | $ 0.14 |  |  |  |  |  |  |  |  |  |  |
Certain employee and directors |  |  |  |  |  |  |  |  |  |  |  |  |
Equity |  |  |  |  |  |  |  |  |  |  |  |  |
Exercised |  |  |  |  | 12,000 |  |  |  | 5,000 |  |  |  |
Exercised, cashless |  |  |  |  |  |  |  |  | 3,000 |  |  |  |
Withheld (in shares) |  |  |  |  | 6,576 |  |  |  | 2,151 |  |  |  |

X
- Definition The number of shares under options that were withheld during the reporting period pertaining to the stock option plan. + References No definition available. + Details
Name: | nssc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWithholdingInPeriod
Namespace Prefix: | nssc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the umber of additional shares authorized to be purchased under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership. + References No definition available. + Details
Name: | nssc_ShareRepurchaseProgramAuthorizedAdditionalNumberOfShares
Namespace Prefix: | nssc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of stock issued as a result of the cashless exercise of stock options. + References No definition available. + Details
Name: | nssc_StockIssuedDuringPeriodSharesCashlessExerciseOfStockOptions
Namespace Prefix: | nssc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount authorized for purchase of share under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 505 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481520/505-30-50-4 + Details
Name: | srt_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | srt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of shares authorized to be purchased under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 505 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481520/505-30-50-4 + Details
Name: | srt_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix: | srt_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate dividends declared during the period for each share of common stock outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the declared dividend will be paid, in YYYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-3 + Details
Name: | us-gaap_DividendPayableDateToBePaidDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the dividend to be paid was declared, in YYYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-3 + Details
Name: | us-gaap_DividendsPayableDateDeclaredDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date the holder must own the stock to be entitled to the dividend, in YYYY-MM-DD format. + References No definition available. + Details
Name: | us-gaap_DividendsPayableDateOfRecordDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- 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. + References No definition available. + Details
Name: | us-gaap_EquityClassOfTreasuryStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of share options (or share units) exercised during the current period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(02) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares remaining authorized to be purchased under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total cost of shares repurchased divided by the total number of shares repurchased. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481549/505-30-45-1 + Details
Name: | us-gaap_TreasuryStockAcquiredAverageCostPerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares that have been repurchased during the period and are being held in treasury. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_TreasuryStockSharesAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DividendsAxis=nssc_O2025Q1DividendsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=nssc_O2025Q2DividendsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=nssc_O2025Q3DividendsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=nssc_O2025Q4DividendsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=nssc_O2026Q1DividendsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=nssc_O2026Q2DividendsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_TitleOfIndividualAxis=srt_DirectorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |