Business Segments (Detail) (CAD) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Revenues and other income
Operating revenues	32,722	[1],[2],[3]	31,053	[1],[2],[3]	30,474	[1],[2],[3]
Investment and other income	207		135		240
Total revenues and other income	32,929		31,188		30,714
Expenses
Exploration	123		83		92
Purchases of crude oil and products	20,155	[4]	18,476	[4]	18,847	[4]
Production and manufacturing	5,288	[5],[6]	4,457	[5],[6]	4,114	[5],[6]
Selling and general	1,082		1,081		1,168
Federal excise tax	1,423	[1]	1,338	[1]	1,320	[1]
Depreciation and depletion	1,110	[6]	761	[6]	764	[6]
Financing costs (note 12)	11	[7]	(1)	[7]	3	[7]
Total expenses	29,192		26,195		26,308
Income before income taxes	3,737		4,993		4,406
Income taxes (note 3)
Current	425		593		955
Deferred	484	[8]	634	[8]	80	[8]
Total income tax expense	909	[9]	1,227	[9]	1,035	[9]
Net income	2,828		3,766		3,371
Cash flows from (used in) operating activities	3,292		4,680		4,489
Capital and exploration expenditures	8,020	[10]	5,683	[10]	4,066	[10]
Property, plant and equipment Cost	47,165		38,765		33,416
Accumulated depreciation and depletion	(15,845)		(14,843)		(14,254)
Net property, plant and equipment	31,320	[11]	23,922	[11]	19,162	[11]
Total assets	37,218	[12]	29,364	[12]	25,429	[12]
Upstream
Revenues and other income
Operating revenues	6,016	[3]	4,674	[3]	5,278	[3]
Intersegment sales	4,026		4,110		4,460
Investment and other income	145		46		168
TOTAL OPERATING REVENUES, INTERSEGMENT SALES, INVESTMENT AND OTHER INCOME	10,187		8,830		9,906
Expenses
Exploration	123		83		92
Purchases of crude oil and products	3,778		3,056		3,581
Production and manufacturing	3,389	[6]	2,704	[6]	2,484	[6]
Selling and general	5		1		7
Depreciation and depletion	636	[6]	498	[6]	528	[6]
Financing costs (note 12)	9		(1)		2
Total expenses	7,940		6,341		6,694
Income before income taxes	2,247		2,489		3,212
Income taxes (note 3)
Current	(14)		72		593
Deferred	549		529		162
Total income tax expense	535		601		755
Net income	1,712		1,888		2,457
Cash flows from (used in) operating activities	1,690		2,625		3,252
Capital and exploration expenditures	7,755	[10]	5,518	[10]	3,880	[10]
Property, plant and equipment Cost	38,819		30,602		25,327
Accumulated depreciation and depletion	(10,749)		(10,146)		(9,747)
Net property, plant and equipment	28,070	[11]	20,456	[11]	15,580	[11]
Total assets	30,553	[12]	22,317	[12]	17,222	[12]
Downstream
Revenues and other income
Operating revenues	25,450	[3]	25,077	[3]	23,909	[3]
Intersegment sales	1,978		2,603		2,784
Investment and other income	59		81		63
TOTAL OPERATING REVENUES, INTERSEGMENT SALES, INVESTMENT AND OTHER INCOME	27,487		27,761		26,756
Expenses
Purchases of crude oil and products	21,628		21,316		21,642
Production and manufacturing	1,695	[6]	1,569	[6]	1,451	[6]
Selling and general	886		935		973
Federal excise tax	1,423		1,338		1,320
Depreciation and depletion	452	[6]	242	[6]	214	[6]
Financing costs (note 12)	2				(1)
Total expenses	26,086		25,400		25,599
Income before income taxes	1,401		2,361		1,157
Income taxes (note 3)
Current	395		486		372
Deferred	(46)		103		(99)
Total income tax expense	349		589		273
Net income	1,052		1,772		884
Cash flows from (used in) operating activities	1,453		1,961		1,315
Capital and exploration expenditures	187	[10]	140	[10]	166	[10]
Property, plant and equipment Cost	7,146		7,038		6,990
Accumulated depreciation and depletion	(4,347)		(3,967)		(3,803)
Net property, plant and equipment	2,799	[11]	3,071	[11]	3,187	[11]
Total assets	5,732	[12]	6,409	[12]	6,700	[12]
Chemical
Revenues and other income
Operating revenues	1,256	[3]	1,302	[3]	1,287	[3]
Intersegment sales	318		299		354
TOTAL OPERATING REVENUES, INTERSEGMENT SALES, INVESTMENT AND OTHER INCOME	1,574		1,601		1,641
Expenses
Purchases of crude oil and products	1,065		1,115		1,222
Production and manufacturing	210	[6]	185	[6]	179	[6]
Selling and general	66		67		64
Depreciation and depletion	12	[6]	12	[6]	13	[6]
Total expenses	1,353		1,379		1,478
Income before income taxes	221		222		163
Income taxes (note 3)
Current	62		67		43
Deferred	(3)		(10)		(2)
Total income tax expense	59		57		41
Net income	162		165		122
Cash flows from (used in) operating activities	198		127		53
Capital and exploration expenditures	9	[10]	4	[10]	4	[10]
Property, plant and equipment Cost	771		765		760
Accumulated depreciation and depletion	(586)		(576)		(560)
Net property, plant and equipment	185	[11]	189	[11]	200	[11]
Total assets	397	[12]	372	[12]	397	[12]
Corporate and Other
Revenues and other income
Investment and other income	3		8		9
TOTAL OPERATING REVENUES, INTERSEGMENT SALES, INVESTMENT AND OTHER INCOME	3		8		9
Expenses
Selling and general	125		78		124
Depreciation and depletion	10	[6]	9	[6]	9	[6]
Financing costs (note 12)					2
Total expenses	135		87		135
Income before income taxes	(132)		(79)		(126)
Income taxes (note 3)
Current	(18)		(32)		(53)
Deferred	(16)		12		19
Total income tax expense	(34)		(20)		(34)
Net income	(98)		(59)		(92)
Cash flows from (used in) operating activities	(49)		(33)		(131)
Capital and exploration expenditures	69	[10]	21	[10]	16	[10]
Property, plant and equipment Cost	429		360		339
Accumulated depreciation and depletion	(163)		(154)		(144)
Net property, plant and equipment	266	[11]	206	[11]	195	[11]
Total assets	581	[12]	704	[12]	1,418	[12]
Consolidation, Eliminations
Revenues and other income
Intersegment sales	(6,322)		(7,012)		(7,598)
TOTAL OPERATING REVENUES, INTERSEGMENT SALES, INVESTMENT AND OTHER INCOME	(6,322)		(7,012)		(7,598)
Expenses
Purchases of crude oil and products	(6,316)		(7,011)		(7,598)
Production and manufacturing	(6)	[6]	(1)	[6]
Total expenses	(6,322)		(7,012)		(7,598)
Income taxes (note 3)
Total assets	(45)	[12]	(438)	[12]	(308)	[12]

[1] Operating revenues include federal excise tax of $1,423 million (2012 - $1,338 million, 2011 - $1,320 million).

[2] Operating revenues include amounts from related parties of $2,385 million (2012 - $2,907 million, 2011 - $2,818 million), (note 16).

[3] Includes export sales to the United States of $5,217 million (2012 - $4,358 million, 2011 - $4,175 million). Export sales to the United States were recorded in all operating segments, with the largest effects in the Upstream segment.

[4] Purchases of crude oil and products include amounts from related parties of $4,104 million (2012 - $3,033 million, 2011 - $3,636 million), (note 16).

[5] Production and manufacturing expenses include amounts to related parties of $319 million (2012 - $241 million, 2011 - $217 million), (note 16).

[6] A 2013 charge in the Downstream segment of $377 million ($280 million, after-tax) associated with the company's decision to convert the Dartmouth refinery to a terminal included the write-down of refinery plant and equipment not included in the terminal conversion of $245 million, reported as part of depreciation and depletion expenses, and decommissioning, environmental and employee-related costs of $132 million, reported as part of production and manufacturing expenses. By the end of 2013, amounts incurred associated with decommissioning, environmental and employee-related costs totalled $40 million.

[7] Cash interest payments in 2013 were $69 million (2012 - $20 million, 2011 - $16 million). The weighted average interest rate on short-term borrowings in 2013 was 1.1 percent (2012 - 1.1 percent).

[8] There were no material net (charges)/credits for the effect of changes in tax laws and rates included in the provisions for deferred income taxes in 2013, 2012 and 2011.

[9] Cash outflow from income taxes, plus investment credits earned, was $911 million in 2013 (2012 - $871 million, 2011 - $667 million).

[10] Capital and exploration expenditures (CAPEX) include exploration expenses, additions to property, plant, equipment and intangibles and additions to capital leases.

[11] Includes property, plant and equipment under construction of $9,234 million (2012 - $13,846 million).

[12] The majority of the goodwill has been assigned to the Downstream segment. Goodwill of $20 million was recognized in 2013 in the Upstream segment as a result of the Celtic acquisition (note 18). There have been no goodwill impairment losses or write-offs due to sales in the past three years. Fair value used in quantitative goodwill impairment tests was Level 3 (unobservable inputs).