v3.20.1

Segment and geographic information - risk (Details) - Revenues, net - Consolidated revenue | 3 Months Ended
--- | ---
Mar. 31, 2020 | Mar. 31, 2019
Niagara Mohawk |  |
Consolidated revenue concentration |  |
Percentage of consolidated revenue | 20.90% | 20.10%
Independent Electricity System Operator |  |
Consolidated revenue concentration |  |
Percentage of consolidated revenue | 14.70% | 15.20%
BC Hydro |  |
Consolidated revenue concentration |  |
Percentage of consolidated revenue | 13.50% | 12.70%
Equistar Chemicals, LP |  |
Consolidated revenue concentration |  |
Percentage of consolidated revenue | 10.30% | 12.50%

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