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Investments in affiliates and joint ventures - Ownership Percentages (Details) | 12 Months Ended
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Dec. 31, 2018
Kivalliq Services Ltd. |
Variable Interest Entity [Line Items] |
NL Partnership Interest in equity method investments | 33.33%
HRN Contracting Ltd. |
Variable Interest Entity [Line Items] |
NL Partnership Interest in equity method investments | 33.33%
Amik Nuna Forestry Services | Variable Interest Entity, Not Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 50.00%
Aroland Nuna | Variable Interest Entity, Not Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 49.00%
Fond Du Lac Nuna | Variable Interest Entity, Not Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 49.00%
Mahiikanuk Nuna | Variable Interest Entity, Not Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 49.00%
Met Nuna | Variable Interest Entity, Not Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 75.00%
Nuna Bauer | Variable Interest Entity, Not Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 50.00%
EDC Nuna Contracting | Variable Interest Entity, Not Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 70.00%
Attawapiskat Nuna | Variable Interest Entity, Not Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 75.00%
Westarc Drilling & Blasting Services Ltd. | Variable Interest Entity, Not Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 30.00%
Deton Cho Nuna | Variable Interest Entity, Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 60.00%
Nuna Deton Cho Winter Road Services | Variable Interest Entity, Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 75.00%
Nuna Deton Cho Contracting | Variable Interest Entity, Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 100.00%

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