XML 100 R69.htm IDEA: XBRL DOCUMENT
v3.19.1

IMPAIRMENT (Details 2) - Average | Dec. 31, 2018 | Jun. 30, 2018 | Dec. 31, 2017
--- | --- | --- | ---
Impairment [Line Items] |  |  |
Average Exchange rates | 1.26 | 1.24 | 1.24
Long term Exchange rates | 1.25 | 1.23 | 1.24
Gold [Member] |  |  |
Impairment [Line Items] |  |  |
Average Commodity prices | 1,299 | 1,311 | 1,300
Long term Commodity Prices | 1,300 | 1,300 | 1,300
Silver [Member] |  |  |
Impairment [Line Items] |  |  |
Average Commodity prices | 17.69 | 18.00 | 19.16
Long term Commodity Prices | 18.17 | 18.17 | 19.25

X
- References No definition available. + Details
Name: | ngd_ImpairmentLineItems
Namespace Prefix: | ngd_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The long term commodity Pricing assumptions used by the entity. + References No definition available. + Details
Name: | ngd_LongTermCommodityPricingAssumptions
Namespace Prefix: | ngd_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition The long term exchange rate assumptions used by the entity. Exchange rate is the ratio of exchange for two currencies. + References No definition available. + Details
Name: | ngd_LongTermForeignExchangeRateAssumptions
Namespace Prefix: | ngd_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition The short term commodity pricing assumptions used by the entity. + References No definition available. + Details
Name: | ngd_ShortTermCommodityPricingAssumptions
Namespace Prefix: | ngd_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition The short term exchange rate assumptions used by the entity. Exchange rate is the ratio of exchange for two currencies. + References No definition available. + Details
Name: | ngd_ShortTermForeignExchangeRateAssumptions
Namespace Prefix: | ngd_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | ifrs-full_HedgingInstrumentsAxis=ngd_Gold1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_HedgingInstrumentsAxis=ngd_SilverMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |