Contract Liability

No definition available.

Name:	c561_ContractLiability
Namespace Prefix:	c561_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contract Liability Current

+ References

No definition available.

+ Details

Name:	c561_ContractLiabilityCurrent
Namespace Prefix:	c561_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contract Obligation That Includes Deferred Consideration, Supply Liability, And Prepayment And Deferred Payment

+ References

No definition available.

+ Details

Name:	c561_ContractObligationThatIncludesDeferredConsiderationSupplyLiabilityAndPrepaymentAndDeferredPayment
Namespace Prefix:	c561_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contract Obligation That Includes Deferred Consideration, Supply Liability, And Prepayment And Deferred Payment, Current

+ References

No definition available.

+ Details

Name:	c561_ContractObligationThatIncludesDeferredConsiderationSupplyLiabilityAndPrepaymentAndDeferredPaymentCurrent
Namespace Prefix:	c561_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Non-Current portion of non-market contracts.

+ References

No definition available.

+ Details

Name:	c561_ContractObligationsExcludingCurrentPortions
Namespace Prefix:	c561_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	c561_ContractObligationsLineItems
Namespace Prefix:	c561_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable beyond one year (or the operating cycle, if longer).

+ References

No definition available.

+ Details

Name:	us-gaap_DeferredCompensationLiabilityClassifiedNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable within one year (or the operating cycle, if longer). Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 710
-SubTopic 10
-Name Accounting Standards Codification
-Section 25
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483070/710-10-25-9

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 30
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483043/710-10-30-2

+ Details

Name:	us-gaap_DeferredCompensationLiabilityCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_OtherCommitmentsAxis=c561_DeferredConsiderationLiabilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_OtherCommitmentsAxis=c561_PrepaidCoalSupplyLiabilityStanwellMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Stanwell Liabilities (Schedule of Contract Obligations) (Details) $ in Thousands, $ in Millions	Jun. 30, 2026 USD ($)	Dec. 31, 2025 USD ($)	Aug. 14, 2018 AUD ($)	Aug. 14, 2018 USD ($)
Contract Obligations [Line Items]
Deferred consideration liability	$ 15,805	$ 0
Stanwell liabilities, Current	28,909	0
Contract obligations, Non-current	0	21,173
Deferred consideration liability	362,318	346,768
Stanwell liabilities, Non-current	592,490	501,795
Stanwell Reserve Area Deferred Consideration [Member]
Contract Obligations [Line Items]
Deferred consideration liability			$ 210.0	$ 155,200
Stanwell Prepaid Coal Supply Liability [Member]
Contract Obligations [Line Items]
Contract obligations	13,104	0
Contract obligations	164,902	155,027
Stanwell Prepayment And Deferred Payment [Member]
Contract Obligations [Line Items]
Contract obligations, Non-current	$ 65,270	$ 0