Income and other taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income tax expense:



For the years ended December 31	2018			2017
Current tax recovery (expense):
Current period before undernoted items	$	(117,496	)	$	(95,402	)
Benefit from unrecognised loss carry forwards	23,860			10,115
Adjustments to prior years	2,609			(217		)
	(91,027		)	(85,504		)
Deferred tax recovery (expense):
Origination and reversal of temporary differences	(56,258		)	23,310
Adjustments to prior years	(2,331		)	200
Change in U.S. tax rate	—			(36,567		)
Change in other jurisdictions tax rates	35			734
Other	(3,910		)	2,039
	(62,464		)	(10,284		)
Total income tax expense	$	(153,491	)	$	(95,788	)

Reconciliation of accounting profit multiplied by applicable tax rates

Income tax expense differs from the amounts that would be obtained by applying the Canadian statutory income tax rate to net income before income taxes as follows:



For the years ended December 31	2018			2017
Income before income taxes	$	811,475		$	470,885
Deduct earnings of associate	(72,001		)	(75,995		)
	739,474			394,890
Canadian statutory tax rate	27.0		%	26.5		%
Income tax expense calculated at Canadian statutory tax rate	(199,658		)	(104,646		)
Increase (decrease) in income tax expense resulting from:
Impact of income and losses taxed in foreign jurisdictions	15,754			30,223
Utilization of unrecognised loss carryforwards and temporary differences	31,325			20,468
Impact of tax rate changes in the U.S.	—			(36,567		)
Impact of tax rate changes in other jurisdictions	35			734
Impact of foreign exchange	(173		)	3,104
Other business taxes	(7,750		)	(4,105		)
Tax effect of recovery (expenses) that are not taxable (deductible) for tax purposes	7,015			(4,112		)
Adjustments to prior years	278			(17		)
Other	(317		)	(870		)
Total income tax expense	$	(153,491	)	$	(95,788	)

Effect of temporary difference, unused tax losses and unused tax credits and analysis of change in deferred income tax liabilities

Analysis of the change in deferred income tax assets and liabilities:



							2018									2017
	Net			Deferred tax assets			Deferred tax liabilities			Net			Deferred tax assets			Deferred tax liabilities
Balance, January 1	$	(164,091	)	$	102,341		$	(266,432	)	$	(153,639	)	$	137,341		$	(290,980	)
Deferred income tax recovery (expense) included in net income	(62,464		)	(44,277		)	(18,187		)	(10,284		)	(34,517		)	24,233
Impact of U.S. tax rate change in other comprehensive income	—			—			—			(8,621		)	(8,621		)	—
Deferred income tax recovery included in other comprehensive income	3,980			1,253			2,727			9,295			8,398			897
Other	893			215			678			(842		)	(260		)	(582		)
Balance, December 31	$	(221,682	)	$	59,532		$	(281,214	)	$	(164,091	)	$	102,341		$	(266,432	)

The tax effect of temporary differences that give rise to deferred income tax liabilities and deferred income tax assets are as follows:



As at				Dec 31 2018									Dec 31 2017
	Net			Deferred tax assets			Deferred tax liabilities			Net			Deferred tax assets			Deferred tax liabilities
Property, plant and equipment	$	(425,743	)	$	(212,087	)	$	(213,656	)	$	(399,391	)	$	(189,368	)	$	(210,023	)
Repatriation taxes	(94,446		)	—			(94,446		)	(87,239		)	—			(87,239		)
Other	(14,930		)	(6,700		)	(8,230		)	(11,670		)	(3,740		)	(7,930		)
	(535,119		)	(218,787		)	(316,332		)	(498,300		)	(193,108		)	(305,192		)
Non-capital loss carryforwards	233,237			233,237			—			244,576			244,576			—
Share-based compensation	10,908			1,170			9,738			19,920			2,946			16,974
Other	69,292			43,912			25,380			69,713			47,927			21,786
	313,437			278,319			35,118			334,209			295,449			38,760
Net deferred income tax assets (liabilities)	$	(221,682	)	$	59,532		$	(281,214	)	$	(164,091	)	$	102,341		$	(266,432	)