Represents authorized amount of stock and debt repurchase program.

No definition available.

Name:	ceix_StockAndDebtRepurchaseProgramAuthorizedAmount
Namespace Prefix:	ceix_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ClassOfStockLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
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-Subparagraph (SX 210.5-02.22(a)(1))
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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3291-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of shares that have been repurchased and retired during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

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-Publisher FASB
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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
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Balance Type:
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- Details

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Stock and Debt Repurchases - Narrative (Details) - USD ($)	1 Months Ended		12 Months Ended
	Nov. 30, 2022	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Aug. 31, 2022	Dec. 31, 2017	Nov. 30, 2017
Class of Stock [Line Items]
Aggregate authorized amount						$ 600,000,000
Stock repurchased and retired during period (in shares)			124,454	0	0
Treasury stock acquired, average cost per share (in dollars per share)			$ 64.18
Stock repurchased during period (in shares)				0	0
Senior Secured Second Lien Notes due 2025
Class of Stock [Line Items]
Repayments of debt			$ 52,074,000	$ 17,092,000	$ 32,064,000
Senior Notes \| Senior Secured Second Lien Notes due 2025
Class of Stock [Line Items]
Stated interest rate percentage			11.00%	11.00%			11.00%	11.00%
Repayments of debt	$ 25,687,000	$ 26,387,000	$ 26,387,000	$ 17,092,000	32,064,000
Repurchased face amount			$ 25,000,000	$ 18,040,000	$ 54,481,000