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Investments in affiliates and joint ventures - Ownership Percentages (Details) | 12 Months Ended
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Dec. 31, 2020
Nuna East Ltd. |
Variable Interest Entity [Line Items] |
NL Partnership Interest in equity method investments | 37.00%
Nuna Pang Contracting Ltd. |
Variable Interest Entity [Line Items] |
NL Partnership Interest in equity method investments | 37.00%
Nuna West Mining Ltd. |
Variable Interest Entity [Line Items] |
NL Partnership Interest in equity method investments | 49.00%
1229181 B.C Ltd. |
Variable Interest Entity [Line Items] |
NL Partnership Interest in equity method investments | 49.00%
North American Nuna Joint Venture |
Variable Interest Entity [Line Items] |
NL Partnership Interest in equity method investments | 50.00%
NAYL Realty Inc. |
Variable Interest Entity [Line Items] |
NL Partnership Interest in equity method investments | 49.00%
BNA Remanufacturing Limited Partnership |
Variable Interest Entity [Line Items] |
NL Partnership Interest in equity method investments | 50.00%
Dene North Site Services Partnership | Variable Interest Entity, Not Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 49.00%
Mikisew North American Limited Partnership | Variable Interest Entity, Not Primary Beneficiary |
Variable Interest Entity [Line Items] |
NL Partnership Interest in VIEs | 49.00%

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