v3.3.1.900

Segment and geographic information - risk (Details) - Revenues, net - Consolidated revenue	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Ontario Electricity Financial Corp (OEFC) | East U.S.
Consolidated revenue concentration
Percentage of consolidated revenue	29.20%	25.80%
San Diego Gas & Electric | West U.S.
Consolidated revenue concentration
Percentage of consolidated revenue	11.00%	15.10%
BC Hydro | West U.S.
Consolidated revenue concentration
Percentage of consolidated revenue	10.00%	9.10%

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