Nature of Operations (Details)	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Wheeler River Joint Venture
Statement [Line Items]
Effective Ownership Interest	95.00%
Ownership Interest, in Key Contractual Arrangements	90.00%
Waterbury Lake Uranium LP
Statement [Line Items]
Ownership interest, Joint Operations	70.32%	69.35%
McClean Lake Joint Venture
Statement [Line Items]
Ownership Interest, in Key Contractual Arrangements	22.50%	22.50%
Midwest Joint Venture
Statement [Line Items]
Ownership Interest, in Key Contractual Arrangements	25.17%	25.17%
Millennium Project
Statement [Line Items]
Ownership interest, Joint Operations	30.099%
Kiggavik Project
Statement [Line Items]
Ownership interest, Joint Operations	33.8118%
Christie Lake
Statement [Line Items]
Ownership interest, Joint Operations	34.4508%
JCU
Statement [Line Items]
Ownership interest, Joint Operations	50.00%	50.00%
JCU \| Wheeler River Joint Venture
Statement [Line Items]
Ownership interest, Joint Operations	5.00%

It represents the effective percentage of proportion of ownership interest in joint operations contractual arrangement.

No definition available.

Name:	dnn_EffectiveProportionOfOwnershipInterestInJointOperationsContractualArrangement
Namespace Prefix:	dnn_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

It represents the percentage of proportion of ownership interest key operations contractual arrangement.

+ References

No definition available.

+ Details

Name:	dnn_ProportionOfOwnershipInterestKeyContractualArrangements
Namespace Prefix:	dnn_
Data Type:	dtr-types:percentItemType
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 members defined in one or many axes of the table.

+ References

No definition available.

+ Details

Name:	dnn_StatementLineItems
Namespace Prefix:	dnn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The proportion of ownership interest in a joint operation attributable to the entity. [Refer: Total for all joint operations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2024-01-01
-Paragraph 21
-Subparagraph a
-Clause iv
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2024-en-r&anchor=para_21_a_iv&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_ProportionOfOwnershipInterestInJointOperation
Namespace Prefix:	ifrs-full_
Data Type:	dtr-2022:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ifrs-full_JointOperationsAxis=dnn_WheelerRiverJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_JointOperationsAxis=dnn_WaterburyLakeUraniumLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_JointOperationsAxis=dnn_McCleanLakeJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_JointOperationsAxis=dnn_MidwestJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_JointOperationsAxis=dnn_MillenniumProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_JointOperationsAxis=dnn_KiggavikProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_JointOperationsAxis=dnn_ChristieLakeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_JointVenturesAxis=dnn_JCUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: