Severance, acquisition and other costs (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Analysis of income and expense [abstract]
Severance	$ (92)	$ (79)
Acquisition and other	(44)	(111)
Total severance, acquisition and other costs	$ (136)	$ (190)
Reduction in management workforce	4.00%

Restructuring And Related Cost, Number Of Positions Eliminated, Period Percent

No definition available.

Name:	bce_RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent1
Namespace Prefix:	bce_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Termination Benefits Expense, Acquisition-Related Costs, And Other Costs

+ References

No definition available.

+ Details

Name:	bce_TerminationBenefitsExpenseAcquisitionRelatedCostsAndOtherCosts
Namespace Prefix:	bce_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of acquisition-related costs recognised as an expense for transactions that are recognised separately from the acquisition of assets and the assumption of liabilities in business combinations. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2018-01-01
-Paragraph B64
-Subparagraph m
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=3&date=2018-03-01&anchor=para_B64_m&doctype=Appendix&seq=2
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_AcquisitionrelatedCostsRecognisedAsExpenseForTransactionRecognisedSeparatelyFromAcquisitionOfAssetsAndAssumptionOfLiabilitiesInBusinessCombination
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	ifrs-full_AnalysisOfIncomeAndExpenseAbstract
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of expense in relation to termination benefits. Termination benefits are employee benefits provided in exchange for the termination of an employee's employment as a result of either: (a) an entity's decision to terminate an employee's employment before the normal retirement date; or (b) an employee's decision to accept an offer of benefits in exchange for the termination of employment. [Refer: Employee benefits expense]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2018-01-01
-Paragraph 171
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2018-03-01&anchor=para_171&doctype=Standard
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_TerminationBenefitsExpense
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration