Interests in Other Entities - Financial Information of Joint Ventures and Associates (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Interests In Other Entities [Abstract]
Carrying amount of interests in joint ventures and associates	$ 1,652	$ 1,579
Our share of:
Net income (loss)	122	51
Other comprehensive income (loss)	(14)	(9)
Total comprehensive income (loss)	$ 108	$ 42

The amount of investments accounted for using the equity method. The equity method is a method of accounting whereby the investment is initially recognised at cost and adjusted thereafter for the post-acquisition change in the investor's share of net assets of the investee. The investor's profit or loss includes its share of the profit or loss of the investee. The investor's other comprehensive income includes its share of the other comprehensive income of the investee. [Refer: At cost [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2021-01-01
-Paragraph 24
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_24_a&doctype=Standard
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2021-01-01
-Paragraph B16
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B16&doctype=Appendix&subtype=B
-URIDate 2021-03-24

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2021-01-01
-Paragraph 54
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_54_e&doctype=Standard
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_InvestmentAccountedForUsingEquityMethod
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Share of the other comprehensive income of associates and joint ventures accounted for using the equity method that will be reclassified to profit or loss, net of tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2021-01-01
-Paragraph 82A
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_82A&doctype=Standard
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_ShareOfOtherComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethodThatWillBeReclassifiedToProfitOrLossNetOfTax
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The entity's share of the profit (loss) of associates and joint ventures accounted for using the equity method. [Refer: Associates [member]; Investments accounted for using equity method; Joint ventures [member]; Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2021-01-01
-Paragraph 23
-Subparagraph g
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_23_g&doctype=Standard
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 8
-IssueDate 2021-01-01
-Paragraph 28
-Subparagraph e
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2021-en-r&anchor=para_28_e&doctype=Standard
-URIDate 2021-03-24

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Note Effective on first application of IFRS 9
-Name IFRS
-Number 4
-IssueDate 2021-01-01
-Paragraph 39M
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2021-en-b&anchor=para_39M_b&doctype=Standard
-URIDate 2021-03-24

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2021-01-01
-Paragraph 82
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_82_c&doctype=Standard
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

The entity's share of the total comprehensive income of associates and joint ventures accounted for using the equity method. [Refer: Associates [member]; Joint ventures [member]; Investments accounted for using equity method]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2021-01-01
-Paragraph B16
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_B16_d&doctype=Appendix&subtype=B
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_ShareOfTotalComprehensiveIncomeOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Interests In Other Entities [Abstract]

+ References

No definition available.

+ Details

Name:	slf_InterestsInOtherEntitiesAbstract
Namespace Prefix:	slf_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration