Consolidated statement of cash flows - CAD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating activities
Net income (loss)		$ (526)	$ 1,212	$ (714)	$ 1,505
Adjustments for non-cash items:
Depreciation and depletion		413	392	866	782
Impairment of intangible assets (note 13)		0	0	20	0
(Gain) loss on asset sales (note 4)		(10)	(11)	(17)	(6)
Inventory write-down to current market value (note 13)		(281)	0	0	0
Deferred income taxes and other		(242)	(471)	(199)	(475)
Changes in operating assets and liabilities:
Accounts receivable		(310)	99	833	(605)
Inventories, materials, supplies and prepaid expenses		117	(40)	(82)	(21)
Income taxes payable		(2)	(9)	(106)	(37)
Accounts payable and accrued liabilities		(46)	(175)	(1,074)	728
All other items - net	[1]	71	29	80	158
Cash flows from (used in) operating activities		(816)	1,026	(393)	2,029
Investing activities
Additions to property, plant and equipment		(205)	(394)	(515)	(825)
Proceeds from asset sales (note 4)		40	14	49	36
Loans to equity companies - net		(7)	(49)	(14)	(103)
Cash flows from (used in) investing activities		(172)	(429)	(480)	(892)
Financing activities
Reduction in finance lease obligations (note 8)		(5)	(6)	(12)	(13)
Dividends paid		(162)	(147)	(326)	(296)
Common shares purchased (note 11)		0	(368)	(274)	(729)
Cash flows from (used in) financing activities		(167)	(521)	(612)	(1,038)
Increase (decrease) in cash		(1,155)	76	(1,485)	99
Cash at beginning of period		1,388	1,011	1,718	988
Cash at end of period	[2]	$ 233	$ 1,087	$ 233	$ 1,087

[1] Included contributions to registered pension plans. (41) (57) (100) (98)

[2] Cash is composed of cash in bank and cash equivalents at cost. Cash equivalents are all highly liquid securities with maturity of three months or less when purchased.