Property, plant and equipment - Reconciliation of Minimum Future Lease Payments (Details) $ in Millions	Dec. 31, 2018 CAD ($)
Disclosure of finance lease and operating lease by lessee [line items]
Minimum future lease payments	$ 2,624
Less:
Future finance costs	(527)
Present value of future lease obligations	2,097
2019
Less:
Future finance costs	(120)
Present value of future lease obligations	466
2020
Less:
Future finance costs	(101)
Present value of future lease obligations	412
2021
Less:
Future finance costs	(83)
Present value of future lease obligations	261
2022
Less:
Future finance costs	(66)
Present value of future lease obligations	210
2023
Less:
Future finance costs	(49)
Present value of future lease obligations	189
THERE- AFTER
Less:
Future finance costs	(108)
Present value of future lease obligations	$ 559

Future Finance Charge On Finance Lease [Abstract]

No definition available.

Name:	bce_FutureFinanceChargeOnFinanceLeaseAbstract
Namespace Prefix:	bce_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

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

- Definition

The amount representing the difference between the future minimum finance lease payments and their present value. Minimum lease payments are payments over the lease term that the lessee is or can be required to make, excluding contingent rent, costs for services and taxes to be paid by, and reimbursed to, the lessor, together with: (a) for a lessee, any amounts guaranteed by the lessee or by a party related to the lessee; or (b) for a lessor, any residual value guaranteed to the lessor by: (i) the lessee; (ii) a party related to the lessee; or (iii) a third party unrelated to the lessor that is financially capable of discharging the obligations under the guarantee.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2019-01-01
-Name IAS
-Number 17
-IssueDate 2018-01-01
-Paragraph 31
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=17&date=2018-03-02&anchor=para_31_b&doctype=Standard&book=b
-URIDate 2018-03-16

+ Details

Name:	ifrs-full_FutureFinanceChargeOnFinanceLease
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of payments over the finance lease term that the lessee is or can be required to make, excluding contingent rent, costs for services and taxes to be paid by, and reimbursed to, the lessor, together with any amounts guaranteed by the lessee or by a party related to the lessee.

+ References

+ Details

Name:	ifrs-full_MinimumFinanceLeasePaymentsPayable
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The present value of minimum finance lease payments payable. [Refer: Minimum finance lease payments payable]

+ References

+ Details

Name:	ifrs-full_MinimumFinanceLeasePaymentsPayableAtPresentValue
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_NotLaterThanOneYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_LaterThanOneYearAndNotLaterThanTwoYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_LaterThanTwoYearsAndNotLaterThanThreeYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_LaterThanThreeYearsAndNotLaterThanFourYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_LaterThanFourYearsAndNotLaterThanFiveYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_LaterThanFiveYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: