XML 103 R72.htm IDEA: XBRL DOCUMENT
v3.19.1

IMPAIRMENT (Details Textual) $ in Millions | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 31, 2018 USD ($) $ / Ounce-oz | Dec. 31, 2018 USD ($) $ / Ounce-oz | Jun. 30, 2018 USD ($) | Dec. 31, 2018 USD ($) $ / Ounce-oz | Dec. 31, 2017 USD ($)
Impairment [Line Items] |  |  |  |  |
Impairment loss net of deferred tax recovery |  |  | $ 282.1 |  |
Impairment loss |  |  |  | $ 1,054.8 | $ 268.4
Insitu Valuation Per Ounce Of Gold | $ / Ounce-oz | 30 | 30 |  | 30 |
Impairment loss recognised in profit or loss | $ 671.1 | $ 671.1 | $ 282.1 | $ 953.2 | $ 181.0
Weighted Average [Member] |  |  |  |  |
Impairment [Line Items] |  |  |  |  |
Discount rate used in current estimate of value in use | 4.00% | 4.00% | 4.50% | 4.00% | 4.00%

X
- Definition The discount rate used in the current estimate of the present value of the future cash flows expected to be derived from an asset or cash-generating unit. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 130 -Subparagraph g -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_130_g&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_DescriptionOfDiscountRatesUsedInCurrentEstimateOfValueInUse
Namespace Prefix: | ifrs-full_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount recognised as a reduction of the carrying amount of an asset or cash-generating unit to its recoverable amount. [Refer: Carrying amount [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 130 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_130_b&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 130 -Subparagraph d -Clause ii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_130_d_ii&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_ImpairmentLoss
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of impairment loss recognised in profit or loss. [Refer: Impairment loss; Profit (loss)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 126 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_126_a&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 129 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_129_a&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_ImpairmentLossRecognisedInProfitOrLoss
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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 amount recognised as a reduction of the carrying amount of an asset or cash-generating unit to its recoverable amount, net of deferred tax recovery. + References No definition available. + Details
Name: | ngd_ImpairmentLossNetOfDeferredTaxRecovery
Namespace Prefix: | ngd_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount recognized from in-Situ valuation of per ounce of gold. + References No definition available. + Details
Name: | ngd_InsituValuationPerOunceOfGold
Namespace Prefix: | ngd_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |