Properties (Details) - CAD CAD in Millions	Dec. 31, 2016	Dec. 31, 2015
Properties including capital leases
Cost	CAD 46,167	CAD 44,827
Accumulated depreciation	12,412	12,203
Net	33,755	32,624
Capital leases included in properties
Cost	1,025	1,394
Accumulated depreciation	266	429
Net	CAD 759	965
Track And Roadway [Member]
Properties including capital leases
Annual rate (in hundredths)	2.00%
Cost	CAD 34,684	33,941
Accumulated depreciation	7,744	7,830
Net	26,940	26,111
Capital leases included in properties
Cost	415	415
Accumulated depreciation	70	66
Net	345	349
Land [Member]
Properties including capital leases
Net	2,446	2,487
Right-of-way access [Member]
Capital leases included in properties
Net	CAD 108	108
Rolling Stock [Member]
Properties including capital leases
Annual rate (in hundredths)	5.00%
Cost	CAD 6,493	6,216
Accumulated depreciation	2,521	2,362
Net	3,972	3,854
Capital leases included in properties
Cost	370	748
Accumulated depreciation	138	301
Net	CAD 232	447
Buildings [Member]
Properties including capital leases
Annual rate (in hundredths)	2.00%
Cost	CAD 1,851	1,791
Accumulated depreciation	652	624
Net	1,199	1,167
Capital leases included in properties
Cost	109	109
Accumulated depreciation	28	26
Net	CAD 81	83
Information technology [Member]
Properties including capital leases
Annual rate (in hundredths)	9.00%
Cost	CAD 1,198	1,067
Accumulated depreciation	628	567
Net	570	500
Internally developed software [Member]
Properties including capital leases
Cost	CAD 106	85
Other [Member]
Properties including capital leases
Annual rate (in hundredths)	4.00%
Cost	CAD 1,941	1,812
Accumulated depreciation	867	820
Net	1,074	992
Capital leases included in properties
Cost	131	122
Accumulated depreciation	30	36
Net	CAD 101	CAD 86

The percent by which an asset loses value on an annual basis.

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- Definition

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

+ References

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Amount before accumulated depreciation of leased physical assets used in the normal conduct of business to produce goods and services.

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The total gross amount less the charge for the use of the long-lived depreciable assets subject to a lease meeting the criteria for capitalization.

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The total charge for the use of long-lived depreciable assets subject to a lease meeting the criteria for capitalization.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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