Represents information pertaining to the acreage of unpatented mining claims contributed by the parent.

No definition available.

Name:	ctgo_AcreageOfUnpatentedMiningClaims
Namespace Prefix:	ctgo_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the amount of economic interest in an investment that may be obtained by an entity.

+ References

No definition available.

+ Details

Name:	ctgo_AmountOfEconomicInterestThatMayBeObtained
Namespace Prefix:	ctgo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the amount of the exploration budget that would need to be funded to maintain the entity's current level of interest.

+ References

No definition available.

+ Details

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

- Definition

Represents the amount of initial investment for the purpose of funding exploration activity.

+ References

No definition available.

+ Details

Name:	ctgo_InitialInvestmentToFundExplorationActivity
Namespace Prefix:	ctgo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the acreage of the leasehold interest contributed by the parent entity.

+ References

No definition available.

+ Details

Name:	ctgo_LeaseholdInterestAcreage
Namespace Prefix:	ctgo_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

The meters of drilling completed.

+ References

No definition available.

+ Details

Name:	ctgo_MetersOfDrillingCompleted
Namespace Prefix:	ctgo_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the area of mining claims acquired during the period.

+ References

No definition available.

+ Details

Name:	ctgo_MiningClaimsAcquiredArea
Namespace Prefix:	ctgo_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of mining claims acquired during the period.

+ References

No definition available.

+ Details

Name:	ctgo_NumberOfMiningClaimsAcquired
Namespace Prefix:	ctgo_
Data Type:	xbrli:integerItemType
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 cash contribution by the parent during the period.

+ References

No definition available.

+ Details

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

- Definition

Represents the percentage of economic interest in an investment that may be obtained by an entity.

+ References

No definition available.

+ Details

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

- Definition

Represents the percentage of the leasehold interest contributed by the parent.

+ References

No definition available.

+ Details

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

- Definition

Represents an entity's ownership percentage in a company as of the balance sheet date.

+ References

No definition available.

+ Details

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

- Definition

Represents the production royalty percentage pertaining to a property.

+ References

No definition available.

+ Details

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

- Definition

Represents the royalty interest sold during the period.

+ References

No definition available.

+ Details

Name:	ctgo_RoyaltyInterestSold
Namespace Prefix:	ctgo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120391452&loc=d3e13212-122682

+ Details

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

- Definition

The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3213-108585

+ Details

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

- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

+ Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=ctgo_ContangoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=ctgo_RoyalGoldMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=ctgo_JEXMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Note 1 - Organization and Business (Details Textual) shares in Millions				1 Months Ended	3 Months Ended	9 Months Ended	63 Months Ended
	Nov. 10, 2017 a	Sep. 29, 2014	Nov. 29, 2010 USD ($) a shares	Sep. 30, 2012 a	Mar. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Oct. 31, 2019	Apr. 26, 2018	Jan. 08, 2015 USD ($)
Long-term Debt, Total					$ 0	$ 0	$ 0
The Joint Venture Company [Member]
Payments to Acquire Interest in Joint Venture							$ 10,000,000
Meters of Drilling Completed								3,073
Exploration Budget, Amount That Would Need to Be Funded to Maintain Current Level of Interest					$ 1,100,000
Equity Method Investment, Ownership Percentage					60.00%	60.00%	60.00%		60.00%
Royal Gold [Member] \| The Joint Venture Company [Member]
Number of Mining Claims Acquired	541
Mining Claims Acquired, Area (Acre) \| a	84,840
Production Royalty Percentage	3.00%
Initial Investment to Fund Exploration Activity										$ 5,000,000
Percentage of Economic Interest That May Be Obtained										40.00%
Amount of Economic Interest That May Be Obtained										$ 30,000,000
Payments to Acquire Interest in Joint Venture						$ 36,700,000	$ 36,700,000
Percentage Ownership in Company					40.00%	40.00%	40.00%
Equity Method Investment, Ownership Percentage									40.00%
Unpatented Mining Claims from the State of Alaska for Gold and Minerals [Member]
Acreage of Unpatented Mining Claims (Acre) \| a			18,021
Native Village of Tetlin Land [Member]
Percentage of Leasehold Interest			100.00%
Leasehold Interest Acreage (Acre) \| a			675,000
Contango [Member]
Parent Contribution			$ 3,500,000
Sale of Stock, Number of Shares Issued in Transaction (in shares) \| shares			1.6
Royal Gold [Member]
Overriding Royalty Interest			3.00%
Royal Gold [Member] \| The Tetlin Lease and Unpatented State of Alaska Mining Claims [Member] \| JEX [Member]
Royalty Interest Sold		3.00%
JEX [Member]
Overriding Royalty Interest				2.00%	3.00%	3.00%	3.00%
JEX [Member] \| Unpatented State of Alaska Mining Claims [Member]
Number of Mining Claims Acquired				474
Mining Claims Acquired, Area (Acre) \| a				71,896
Production Royalty Percentage				2.00%