XML 84 R70.htm IDEA: XBRL DOCUMENT
v3.19.2

Shared-Based Compensation - Summary of Number of Awards Granted and Grand Date Fair Value (Detail) shares in Thousands | 6 Months Ended
--- | ---
Jun. 30, 2019 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Grant Date Fair Value (in USD per share) | $ 7.93
TSR Awards |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Number of awards granted in fair values (in shares) | shares | 136
Grant Date Fair Value (in USD per share) | $ 9.28
ROIC Awards |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Number of awards granted in fair values (in shares) | shares | 174
Grant Date Fair Value (in USD per share) | $ 7.93

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
- Definition Net number of non-option equity instruments granted to participants. + 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)(1)(iv)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

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: |