Consolidated statement of shareholders' equity - CAD ($) $ in Millions	Total	Common shares at stated value (note 11)	Earnings reinvested	Accumulated other comprehensive income (loss) (note 18)
At beginning of period at Dec. 31, 2018		$ 1,446	$ 24,560	$ (1,517)
Net income (loss) for the period	$ 293		293
Share purchases at stated value		(19)
Share purchases in excess of stated value			(342)
Dividends declared			(147)
Other comprehensive income (loss)	45			45
At end of period at Mar. 31, 2019	24,319	1,427	24,364	(1,472)
At beginning of period at Dec. 31, 2018		1,446	24,560	(1,517)
Share purchases at stated value		(71)
At end of period at Dec. 31, 2019	24,276	1,375	24,812	(1,911)
Net income (loss) for the period	(188)		(188)
Share purchases at stated value		(18)
Share purchases in excess of stated value			(256)
Dividends declared			(162)
Cumulative effect of accounting change (note 5)			(2)
Other comprehensive income (loss)	(80)			(80)
At end of period at Mar. 31, 2020	$ 23,570	$ 1,357	$ 24,204	$ (1,991)