Capital Structure Financial Policies - (Details) CAD in Millions	12 Months Ended
Dec. 31, 2017 CAD	Dec. 31, 2016 CAD	Dec. 31, 2015 CAD
Components of Ratio
Short-term debt	CAD 2,136.0	CAD 1,273.0
Current portion of long-term debt	71.0	54.0
Long-term debt	13,372.0	16,103.0
Total debt	15,579.0	17,430.0
Less: Cash and cash equivalents	2,672.0	3,016.0	CAD 4,049.0
Net debt	12,907.0	14,414.0
Shareholders' equity	45,383.0	44,630.0	CAD 39,039.0
Total capitalization (total debt plus shareholders' equity)	60,962.0	62,060.0
Funds from operations	CAD 9,139.0	CAD 5,988.0
Net debt to funds from operations	1.4	2.4
Total debt to total debt plus shareholders' equity	26	28
Maximum
CAPITAL STRUCTURE FINANCIAL POLICIES
Percentage of Financial covenant	65
Components of Ratio
Net debt to funds from operations	3.0	3.0

The amount of outstanding funds that the entity is obligated to repay.

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The amount of cash on hand and demand deposits, along with short-term, highly liquid investments that are readily convertible to known amounts of cash and that are subject to an insignificant risk of changes in value. [Refer: Cash; Cash equivalents]

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The cash inflow (outflow) from the entity's operations before changes in working capital.

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The current portion of non-current borrowings. [Refer: Borrowings]

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The amount of residual interest in the assets of the entity after deducting all its liabilities.

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The amount of net debt of the entity.

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This element represents the total capitalization of the entity which is comprised of its equity and debt.

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Percentage of financial covenant under the company's banking and debt arrangements.

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Represents the ratio of debt to total capitalization which consists of debt and equity.

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Ratio of debt to funds from operations

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