Bank overdrafts and short-term borrowings - Summary of Weighted Average Interest Rates on Bank Overdrafts and Short-Term Borrowings (Detail)	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Disclosure of detailed information about borrowings [abstract]
Bank overdrafts	7.02%	7.81%
Borrowings	6.37%	5.65%

Weighted average interest rates on short-term borrowings.

No definition available.

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Namespace Prefix:	ntz_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration