Represents the amount of advance royalties to be paid per year.

No definition available.

Name:	ctgo_AdvanceRoyaltiesToBePaidPerYear
Namespace Prefix:	ctgo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the amount of annual claim rentals payable, as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	ctgo_AnnualClaimRentals
Namespace Prefix:	ctgo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the contractual exploration costs to be paid per year, pursuant to the terms of the agreement.

+ References

No definition available.

+ Details

Name:	ctgo_ContractualAnnualExplorationCosts
Namespace Prefix:	ctgo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the reduction in the percentage of the royalty payable.

+ References

No definition available.

+ Details

Name:	ctgo_DecreaseInRoyaltyRates
Namespace Prefix:	ctgo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the extension of the term of leases and concessions on undeveloped acreage.

+ References

No definition available.

+ Details

Name:	ctgo_ExtensionOfTermOfLeasesAndConcessionsOnUndevelopedAcreage
Namespace Prefix:	ctgo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the payments that have been made, inception-to-date, to reduce the royalty rate under an agreement.

+ References

No definition available.

+ Details

Name:	ctgo_InceptionToDatePaymentsToReduceRoyaltyRate
Namespace Prefix:	ctgo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents an increase in the percentage of the royalty payable.

+ References

No definition available.

+ Details

Name:	ctgo_IncreaseInRoyaltyRates
Namespace Prefix:	ctgo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the initial term of leases and concessions on undeveloped acreage.

+ References

No definition available.

+ Details

Name:	ctgo_InitialTermOfLeasesAndConcessionsOnUndevelopedAcreage
Namespace Prefix:	ctgo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the overriding royalty interest the company would be required to pay if any of the properties are placed into commercial production.

+ References

No definition available.

+ Details

Name:	ctgo_OverridingRoyaltyInterest
Namespace Prefix:	ctgo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the amount of payment that the lessor may make to the lessee in order to increase the royalty rate by a specified percentage.

+ References

No definition available.

+ Details

Name:	ctgo_PaymentThatLessorMayPayToLesseeToIncreaseRoyaltyRate
Namespace Prefix:	ctgo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the royalty rate required to be paid under an agreement.

+ References

No definition available.

+ Details

Name:	ctgo_RoyaltyRate
Namespace Prefix:	ctgo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=ctgo_TetlinLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=ctgo_Scenario1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=ctgo_Scenario2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=ctgo_Scenario3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=ctgo_TheJointVentureCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=ctgo_GoldPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=ctgo_TetlinLeaseAndCertainOtherPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=ctgo_RoyalGoldMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=ctgo_AdditionalPropertiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ctgo_NativeVillageOfTetlinLandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 10 - Commitments and Contingencies (Details Textual) - USD ($)			1 Months Ended	12 Months Ended
	Jul. 15, 2012	Jul. 01, 2008	Jul. 31, 2008	Jun. 30, 2018
Tetlin Lease [Member]
Inception-to-date Payments to Reduce Royalty Rate				$ 225,000
Decrease in Royalty Rates				0.75%
Tetlin Lease [Member] \| Scenario 1 [Member]
Increase in Royalty Rates				0.25%
Payment that Lessor May Pay to Lessee to Increase Royalty Rate				$ 150,000
Tetlin Lease [Member] \| Scenario 2 [Member]
Increase in Royalty Rates				0.50%
Payment that Lessor May Pay to Lessee to Increase Royalty Rate				$ 300,000
Tetlin Lease [Member] \| Scenario 3 [Member]
Increase in Royalty Rates				0.75%
Payment that Lessor May Pay to Lessee to Increase Royalty Rate				$ 450,000
Tetlin Lease [Member] \| Minimum [Member]
Advance Royalties to Be Paid Per Year	$ 75,000			$ 50,000
Tetlin Lease [Member] \| The Joint Venture Company [Member]
Contractual Annual Exploration Costs			$ 350,000
Tetlin Lease [Member] \| The Joint Venture Company [Member] \| Minimum [Member]
Royalty Rate			2.00%	1.25%
Tetlin Lease [Member] \| The Joint Venture Company [Member] \| Maximum [Member]
Royalty Rate			5.00%	4.25%
Gold Properties [Member]
Annual Claim Rentals				$ 155,505
Tetlin Lease and Certain Other Properties [Member] \| The Joint Venture Company [Member] \| Royal Gold [Member]
Overriding Royalty Interest				3.00%
Additional Properties [Member] \| The Joint Venture Company [Member] \| Royal Gold [Member]
Overriding Royalty Interest				2.00%
Native Village of Tetlin Land [Member]
Initial Term of Leases and Concessions on Undeveloped Acreage			10 years
Extension of Term of Leases and Concessions on Undeveloped Acreage		10 years