Earnings Per Share - Weighted Average Common Shares (Detail) - shares	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Weighted average ordinary shares and adjusted weighted average ordinary shares [abstract]
Weighted-average number of common shares outstanding	438,384,963	450,543,811	441,398,585	450,349,667
Weighted-average number of vested DSUs	115,676	130,015	116,749	131,439
Basic	438,500,639	450,673,826	441,515,334	450,481,106
Effect of stock options and TRSUs	110,735	531,006	193,994	544,701
Diluted	438,611,374	451,204,832	441,709,328	451,025,807

The weighted average number of ordinary shares outstanding plus the weighted average number of ordinary shares that would be issued on the conversion of all the dilutive potential ordinary shares into ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2025-01-01
-Paragraph 70
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=33&code=ifrs-tx-2025-en-r&anchor=para_70_b&doctype=Standard
-URIDate 2025-03-27

+ Details

Name:	ifrs-full_AdjustedWeightedAverageShares
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The potential dilutive effect on the weighted average number of ordinary shares that relate to the assumed exercise of the entity's share options.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 33
-IssueDate 2025-01-01
-Paragraph 70
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=33&code=ifrs-tx-2025-en-r&anchor=para_70_b&doctype=Standard
-URIDate 2025-03-27

+ Details

Name:	ifrs-full_DilutiveEffectOfShareOptionsOnNumberOfOrdinaryShares
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average number of instruments used in calculating basic earnings (loss) per instrument for an equity instrument that participates in profit with ordinary shares according to a predetermined formula. [Refer: Basic earnings (loss) per instrument, participating equity instruments other than ordinary shares]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 33
-IssueDate 2025-01-01
-Paragraph A14
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=33&code=ifrs-tx-2025-en-r&anchor=para_A14&doctype=Appendix&subtype=A
-URIDate 2025-03-27

+ Details

Name:	ifrs-full_WeightedAverageNumberOfInstrumentsUsedInCalculatingBasicEarningsLossPerInstrumentParticipatingEquityInstrumentsOtherThanOrdinaryShares
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of ordinary shares outstanding at the beginning of the period, adjusted by the number of ordinary shares bought back or issued during the period multiplied by a time-weighting factor.

+ References

+ Details

Name:	ifrs-full_WeightedAverageShares
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Weighted average number of vested DSUs.

+ References

No definition available.

+ Details

Name:	tri_WeightedAverageNumberOfVestedDSUs
Namespace Prefix:	tri_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration