Segmented information (Tables)

12 Months Ended

Dec. 31, 2015

Segment Reporting [Abstract]

Results of Operations and Assets for Segments

The results of operations and assets for these segments are reflected in the tables below.

	Year ended December 31, 2015
	Generation			Distribution			Corporate			Total
Revenue	$	244,751		$	783,104		$	—		$	1,027,855
Fuel and power purchased	27,990			348,883			—			376,873
Net revenue	216,761			434,221			—			650,982
Operating expenses	63,601			213,750			1,210			278,561
Administrative expenses	10,822			21,570			8,283			40,675
Depreciation and amortization	67,293			82,513			—			149,806
Gain on foreign exchange	—			—			(2,631		)	(2,631		)
Operating income (loss) from continuing operations	75,045			116,388			(6,862		)	184,571
Interest expense	29,395			34,971			1,627			65,993
Interest, dividend, equity and other income	(1,154		)	(3,974		)	(3,967		)	(9,095		)
Other expenses (gain)	(5,623		)	391			2,656			(2,576		)
Earnings (loss) before income taxes	$	52,427		$	85,000		$	(7,178	)	$	130,249
Property, plant and equipment	$	1,895,617		$	1,914,980		$	63,087		$	3,873,684
Equity-method investees	44,638			769			7,066			52,473
Total assets	2,345,905			2,532,894			112,926			4,991,725
Capital expenditures	55,992			141,445			6,758			204,195

21. Segmented information (continued)

	Year ended December 31, 2014
	Generation			Distribution			Corporate			Total
Revenue	$	218,765		$	722,849		$	—		$	941,614
Fuel and power purchased	39,264			381,622			—			420,886
Net revenue	179,501			341,227			—			520,728
Operating expenses	55,482			178,248			308			234,038
Administrative expenses	13,457			19,947			1,288			34,692
Depreciation and amortization	58,248			53,671			2,128			114,047
Gain on foreign exchange	—			—			(1,112		)	(1,112		)
	52,314			89,361			(2,612		)	139,063
Interest expense	33,868			27,139			1,411			62,418
Interest, dividend and other income	(1,187		)	(3,369		)	(3,202		)	(7,758		)
Other expense (gain)	48			300			11,606			11,954
Earnings (loss) before income taxes	$	19,585		$	65,291		$	(12,427	)	$	72,449
Property, plant and equipment	$	1,687,465		$	1,531,166		$	59,791		$	3,278,422
Equity-method investees	3,520			500			2,578			6,598
Total assets	1,896,265			2,098,244			108,339			4,102,848
Capital expenditures	201,063			176,849			54,461			432,373

Information on Operations by Geographic Area

Information on operations by geographic area is as follows:

	2015		2014
Revenue
Canada	$	86,977	$	92,267
United States	940,878		849,347
	$	1,027,855	$	941,614
Property, plant and equipment
Canada	$	592,598	$	590,580
United States	3,281,086		2,687,842
	$	3,873,684	$	3,278,422
Intangible assets
Canada	$	40,186	$	25,601
United States	37,777		28,410
	$	77,963	$	54,011