XML 123 R77.htm IDEA: XBRL DOCUMENT
v3.22.4

Derivative instruments - Impact of movements in market commodity prices (Details) oz in Millions, lb in Millions | Dec. 31, 2022 lb oz | Dec. 31, 2021 lb oz
--- | --- | ---
Financial Instruments [Abstract] |  |
Gold ounces | oz | 0.5 | 0.7
Copper pounds | lb | 1.4 | 1.0

X
- Definition Financial Instruments [Abstract] + References No definition available. + Details
Name: | ngd_FinancialInstrumentsAbstract
Namespace Prefix: | ngd_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The volume of copper subject to final pricing net of outstanding swaps. + References No definition available. + Details
Name: | ngd_VolumeOfCopperSubjectToFinalPricingNetOfOutstandingSwaps
Namespace Prefix: | ngd_
Data Type: | dtr-types:massItemType
Balance Type: | na
Period Type: | instant

X
- Definition The volume of gold subject to final pricing net of outstanding swaps. + References No definition available. + Details
Name: | ngd_VolumeOfGoldSubjectToFinalPricingNetOfOutstandingSwaps
Namespace Prefix: | ngd_
Data Type: | dtr-types:massItemType
Balance Type: | na
Period Type: | instant