Early Retirement Program (Details) $ in Thousands	6 Months Ended
Jun. 30, 2025 USD ($)
Restructuring and Related Activities [Abstract]
PostemploymentBenefitsTotalExpense	$ 1,600
Postemployment Benefits, Period Expense	$ 400

The total expense, both incurred and future, to be incurred related to postemployment benefits.

No definition available.

Name:	nnbr_PostemploymentBenefitsTotalExpense
Namespace Prefix:	nnbr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant