Financial Instruments And Risk Management - Financial Liabilities (Details) - CAD CAD in Millions	Dec. 31, 2017	Dec. 31, 2016
Derivatives
Financial Liabilities Offsetting
Gross Liabilities	CAD (1,231)	CAD (1,819)
Gross Assets Offset	1,052	1,610
Net Amounts Presented	(179)	(209)
Accounts Payable
Financial Liabilities Offsetting
Gross Liabilities	(2,270)	(1,975)
Gross Assets Offset	1,252	946
Net Amounts Presented	(1,018)	(1,029)
Financial liabilities
Financial Liabilities Offsetting
Gross Liabilities	(3,501)	(3,794)
Gross Assets Offset	2,304	2,556
Net Amounts Presented	CAD (1,197)	CAD (1,238)

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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- Definition

The amount of financial assets set off against financial liabilities when an entity: (a) currently has a legally enforceable right to set off the recognised amounts; and (b) intends either to settle on a net basis, or to realise the asset and settle the liability simultaneously. [Refer: Financial assets; Financial liabilities]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

The gross amount of recognised financial liabilities that are subject either to offsetting or to an enforceable master netting arrangement or similar agreement. [Refer: Financial liabilities]

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- Definition

The net amount of financial liabilities that are subject either to offsetting or to an enforceable master netting arrangement or similar agreement, presented in the statement of financial position. [Refer: Financial liabilities]

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