XML 72 R60.htm IDEA: XBRL DOCUMENT
v3.21.2

Shared-Based Compensation - Additional Information (Detail) shares in Thousands, $ in Millions | 9 Months Ended
--- | ---
Sep. 30, 2021 USD ($) shares
Restricted stock |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Stock units issued (in shares) | 459
Total grant-date fair value of restricted stock, vested | $ | $ 2.8
TSR Awards |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Stock units issued (in shares) | 142
Award performance period | 3 years
Percentage of shares issuable based on threshold performance | 50.00%
Percentage of shares issuable based on target performance | 100.00%
Percentage of shares issuable based on maximum performance | 150.00%
ROIC Awards |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Stock units issued (in shares) | 172
Percentage of shares issuable based on target performance | 100.00%
Employees | Restricted stock |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Stock awards granted vesting period | 3 years
Non-executive Directors | Restricted stock |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Stock awards granted vesting period | 1 year

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Period + References No definition available. + Details
Name: | nnbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPerformancePeriod
Namespace Prefix: | nnbr_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangement by share based payment award percentage of shares issuable based on threshold performance. + References No definition available. + Details
Name: | nnbr_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfSharesIssuableBasedOnThresholdPerformance
Namespace Prefix: | nnbr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangement by share-based payment award percentage of shares issuable based on maximum performance. + References No definition available. + Details
Name: | nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardPercentageOfSharesIssuableBasedOnMaximumPerformance
Namespace Prefix: | nnbr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangement by share-based payment award, percentage of shares Issuable based on target performance. + References No definition available. + Details
Name: | nnbr_ShareBasedCompensationArrangementBySharebasedPaymentAwardPercentageOfSharesIssuableBasedOnTargetPerformance
Namespace Prefix: | nnbr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodTotalFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=nnbr_PerformanceSharesTsrAwardsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=nnbr_PerformanceSharesReturnOnInvestedCapitalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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