Represents the required asset coverage ratio under the terms of the agreement.

No definition available.

Name:	cog_DebtInstrumentCovenantAssetCoverageRatio
Namespace Prefix:	cog_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the ratio of current assets to current liabilities.

+ References

No definition available.

+ Details

Name:	cog_DebtInstrumentCovenantCurrentRatio
Namespace Prefix:	cog_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of trailing quarters used to calculate the annual coverage ratio.

+ References

No definition available.

+ Details

Name:	cog_DebtInstrumentCovenantNumberOfTrailingQuartersForCalculationOfAnnualCoverageRatio
Namespace Prefix:	cog_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of the entity's total indebtedness to its borrowing base under the credit facility under the fourth level.

+ References

No definition available.

+ Details

Name:	cog_LineOfCreditFacilityBasisSpreadIncreaseTotalIndebtednessPercentageOfBorrowingBaseLevelFour
Namespace Prefix:	cog_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of the entity's total indebtedness to its borrowing base under the credit facility under the first level.

+ References

No definition available.

+ Details

Name:	cog_LineOfCreditFacilityBasisSpreadIncreaseTotalIndebtednessPercentageOfBorrowingBaseLevelOne
Namespace Prefix:	cog_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of the entity's total indebtedness to its borrowing base under the credit facility under the third level.

+ References

No definition available.

+ Details

Name:	cog_LineOfCreditFacilityBasisSpreadIncreaseTotalIndebtednessPercentageOfBorrowingBaseLevelThree
Namespace Prefix:	cog_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of the entity's total indebtedness to its borrowing base under the credit facility under the second level.

+ References

No definition available.

+ Details

Name:	cog_LineOfCreditFacilityBasisSpreadIncreaseTotalIndebtednessPercentageOfBorrowingBaseLevelTwo
Namespace Prefix:	cog_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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

- Details

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

- Definition

The effective interest rate during the reporting period.

+ 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 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of long-term debt outstanding.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermDebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Debt and Credit Agreements (Details 3) (Revolving Credit Facility, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 Q	Dec. 31, 2012	Dec. 31, 2011
Debt
Number of trailing quarters used to calculate annual coverage ratio	4
Availability under the credit facility	$ 939.0
Weighted-average effective interest rates (as a percent)	2.30%	3.00%	4.10%
Weighted-average interest rate (as a percent)	2.00%	2.20%
Greater than
Debt
Commitment fee percentage	0.375%
Current ratio	1.0
Asset coverage ratio	1.75
Percentage of the entity's total indebtedness to its borrowing base under the credit facility under the first level	25.00%
Percentage of the entity's total indebtedness to its borrowing base under the credit facility under the second level	50.00%
Percentage of the entity's total indebtedness to its borrowing base under the credit facility under the third level	75.00%
Percentage of the entity's total indebtedness to its borrowing base under the credit facility under the fourth level	90.00%
Less than or equal to
Debt
Commitment fee percentage	0.50%
Eurodollar Loans
Debt
Description of variable rate basis	Euro-Dollars (LIBOR)
ABR Loans
Debt
Description of variable rate basis	Base Rate (Prime)
Less than 25 percent \| Eurodollar Loans
Debt
Margin (as a percent)	1.50%
Less than 25 percent \| ABR Loans
Debt
Margin (as a percent)	0.50%
Greater than equal to 25 percent but less than 50 percent \| Eurodollar Loans
Debt
Margin (as a percent)	1.75%
Greater than equal to 25 percent but less than 50 percent \| ABR Loans
Debt
Margin (as a percent)	0.75%
Greater than equal to 50 percent but less than 75 percent \| Eurodollar Loans
Debt
Margin (as a percent)	2.00%
Greater than equal to 50 percent but less than 75 percent \| ABR Loans
Debt
Margin (as a percent)	1.00%
Greater than equal to 75 percent but less than 90 percent \| Eurodollar Loans
Debt
Margin (as a percent)	2.25%
Greater than equal to 75 percent but less than 90 percent \| ABR Loans
Debt
Margin (as a percent)	1.25%
Greater than and equal to 90 percent \| Eurodollar Loans
Debt
Margin (as a percent)	2.50%
Greater than and equal to 90 percent \| ABR Loans
Debt
Margin (as a percent)	1.50%