Daily volume weighted average price.

No definition available.

Name:	crk_DailyVolumeWeightedAveragePrice
Namespace Prefix:	crk_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument, convertible, percentage of debt converted.

+ References

No definition available.

+ Details

Name:	crk_DebtInstrumentConvertiblePercentageOfDebtConverted
Namespace Prefix:	crk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt instrument, interest rate, payment in kind.

+ References

No definition available.

+ Details

Name:	crk_DebtInstrumentInterestRatePaymentInKind
Namespace Prefix:	crk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt restructuring costs.

+ References

No definition available.

+ Details

Name:	crk_DebtRestructuringCosts
Namespace Prefix:	crk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Gain (losses) on conversion of debt.

+ References

No definition available.

+ Details

Name:	crk_GainLossesOnConversionOfDebt
Namespace Prefix:	crk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Long term debt principal amount.

+ References

No definition available.

+ Details

Name:	crk_LongTermDebtPrincipalAmount
Namespace Prefix:	crk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum accrued interest payable in kind.

+ References

No definition available.

+ Details

Name:	crk_MaximumAccruedInterestPayableInKind
Namespace Prefix:	crk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Maximum notes issuable for toggle interest paid in kind.

+ References

No definition available.

+ Details

Name:	crk_MaximumNotesIssuableForToggleInterestPaidInKind
Namespace Prefix:	crk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

+ Details

Name:	us-gaap_DebtConversionConvertedInstrumentAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

+ Details

Name:	us-gaap_DebtConversionConvertedInstrumentSharesIssued1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of warrants issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

+ Details

Name:	us-gaap_DebtConversionConvertedInstrumentWarrantsOrOptionsIssued1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21506-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21521-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21475-112644

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(5))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionRatio1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the debt agreement requires the first payment to be made, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentDateOfFirstRequiredPayment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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

- Definition

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

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Amount of gain (loss) from the difference between the repurchase price of a debt instrument initially issued by the entity and the net carrying amount of the debt at the time of its repurchase.

+ References

No definition available.

+ Details

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

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629

+ Details

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

- 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

No definition available.

+ Details

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

- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

+ Details

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

- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

Name:	us-gaap_WriteOffOfDeferredDebtIssuanceCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_DebtConversionByUniqueDescriptionAxis=crk_ExchangeOfferMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=crk_SeniorSecuredToggleNotesTenPercentDueTwoThousandTwentyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=crk_ConvertibleSecondLienPaymentInKindNotesSevenPointSevenFivePercentDueTwoThousandNineteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=crk_ConvertibleSecondLienPaymentInKindNotesNinePointFivePercentDueTwoThousandTwentyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=crk_ConvertibleSecondLienPaymentInKindNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=crk_SeniorSecuredNotesTenPercentDueTwoThousandTwentyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=crk_SeniorNotesSevenPointSevenFivePercentDueTwoThousandNineteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=crk_SeniorNotesNinePointFivePercentDueTwoThousandTwentyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=crk_SeniorNotesSevenPointSevenFivePercentDueTwoThousandNineteenAndSeniorNotesNinePointFivePercentDueTwoThousandTwentyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtConversionByUniqueDescriptionAxis=crk_PaymentInCashMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Long-term Debt - Additional Information (Detail)		3 Months Ended				8 Months Ended	12 Months Ended
Long-term Debt - Additional Information (Detail)	Sep. 06, 2016 USD ($) shares	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Sep. 05, 2016 USD ($) shares	Dec. 31, 2017 USD ($) Day $ / shares	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Debt Instrument [Line Items]
Gain on extinguishment of debt		$ (1,064,000)	$ 100,540,000	$ 56,196,000	$ 33,380,000			$ 189,052,000	$ 78,741,000
Unamortized debt issuance costs		$ 16,183,000					$ 10,685,000	$ 16,183,000
Loss from write-off of deferred loan costs									3,700,000
Exchange Offer
Debt Instrument [Line Items]
Percentage of outstanding senior notes	98.00%
Warrants exercisable \| shares	1,917,342
10% Senior Secured Toggle Notes due 2020
Debt Instrument [Line Items]
Interest payment terms							payable on March 15 and September 15, and the notes mature on March 15, 2020
Maturity of senior notes							Mar. 15, 2020
Accrued interest by issuing additional notes							$ 75,000,000
Interest rate on senior notes, payment in kind							12.25%
Additional notes outstanding							$ 91,900,000
Interest rate on senior notes		10.00%					10.00%	10.00%
Principal		$ 697,195,000					$ 697,195,000	$ 697,195,000
10% Senior Secured Toggle Notes due 2020 \| Exchange Offer
Debt Instrument [Line Items]
Principal amount of notes issued	$ 697,200,000
Interest rate on senior notes	10.00%
Transaction costs								$ 4,500,000
7¾% Convertible Second Lien PIK Notes due 2019
Debt Instrument [Line Items]
Interest payment terms							payable on April 1 and October 1
Maturity of senior notes							Apr. 01, 2019
Interest rate on senior notes		7.75%					7.75%	7.75%
Principal		$ 268,432,000					$ 284,442,000	$ 268,432,000
7¾% Convertible Second Lien PIK Notes due 2019 \| Exchange Offer
Debt Instrument [Line Items]
Principal amount of notes issued	$ 270,600,000
Interest rate on senior notes	7.75%
9½% Convertible Second Lien PIK Notes due 2020
Debt Instrument [Line Items]
Interest payment terms							payable on June 15 and December 15
Maturity of senior notes							Jun. 15, 2020
Interest payment commencing date							Dec. 15, 2016
Interest rate on senior notes		9.50%					9.50%	9.50%
Principal		$ 174,182,000					$ 187,062,000	$ 174,182,000
9½% Convertible Second Lien PIK Notes due 2020 \| Exchange Offer
Debt Instrument [Line Items]
Principal amount of notes issued	$ 169,700,000
Interest rate on senior notes	9.50%
Convertible Second Lien PIK Notes
Debt Instrument [Line Items]
Debt instrument convertible conversion ratio							0.0812
Debt instrument convertible threshold consecutive trading days period \| Day							15
Convertible Second Lien PIK Notes \| Exchange Offer
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ 6,500,000
Convertible Second Lien PIK Notes \| Minimum
Debt Instrument [Line Items]
Daily volume weighted average price \| $ / shares							$ 12.32
10% Senior Secured Notes due 2020
Debt Instrument [Line Items]
Principal	$ 2,800,000
10% Senior Secured Notes due 2020 \| Exchange Offer
Debt Instrument [Line Items]
Interest rate on senior notes	10.00%
Principal amount of notes repurchased	$ 697,200,000
Gain (loss) on exchange of debt	0
7¾% Senior Notes due 2019
Debt Instrument [Line Items]
Interest rate on senior notes		7.75%					7.75%	7.75%
Principal amount of notes repurchased						$ 87,500,000			23,900,000
Principal	$ 18,000,000	$ 17,959,000					$ 17,959,000	$ 17,959,000
7¾% Senior Notes due 2019 \| Exchange Offer
Debt Instrument [Line Items]
Interest rate on senior notes	7.75%
Principal amount of notes repurchased	$ 270,600,000
9½% Senior Notes due 2020
Debt Instrument [Line Items]
Interest rate on senior notes		9.50%					9.50%	9.50%
Principal amount of notes repurchased						$ 19,800,000			105,600,000
Principal	$ 4,900,000	$ 4,860,000					$ 4,860,000	$ 4,860,000
Aggregate purchase price of debt									42,700,000
9½% Senior Notes due 2020 \| Exchange Offer
Debt Instrument [Line Items]
Interest rate on senior notes	9.50%
Principal amount of notes repurchased	$ 169,700,000
7 3/4% Senior Notes due 2019 and 9 1/2% Senior Notes due 2020
Debt Instrument [Line Items]
Gain on extinguishment of debt								89,600,000
Common stock shares exchanged for repayment of principal amount \| shares						2,748,403
Gain on repurchased amount of notes									$ 82,400,000
7 3/4% Senior Notes due 2019 and 9 1/2% Senior Notes due 2020 \| Exchange Offer
Debt Instrument [Line Items]
Gain on extinguishment of debt								$ 106,200,000
7 3/4% Senior Notes due 2019 and 9 1/2% Senior Notes due 2020 \| Payment In Cash
Debt Instrument [Line Items]
Senior notes exchanged in cash						$ 3,500,000