Represents the cumulative income (loss), from inception to the balance sheet date, of an equity method investment.

No definition available.

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

- Definition

Te total cash and noncash contributions to equity method investment.

+ References

No definition available.

+ Details

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

- Definition

Represents entity's share of losses from equity method investment including losses that are not recognized in earnings

+ References

No definition available.

+ Details

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

- Definition

Represents the suspended losses incurred during the period. This may be for, example, an equity method investment.

+ References

No definition available.

+ Details

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

- Definition

This element represents the aggregate cost of investments accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

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

- 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://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

+ Details

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

- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481664/323-10-45-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(10))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 25
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-25

+ Details

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

- Details

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

Note 5 - Investment in the Peak Gold JV (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Jun. 30, 2022	Jun. 29, 2021	Sep. 30, 2020	Sep. 29, 2020	Jan. 08, 2015
Equity Method Investments	$ 0		$ 0		$ 0
The Joint Venture Company [Member]
Equity Method Investment, Aggregate Cost	$ 33,800,000		33,800,000						$ 1,400,000
Equity Method Investment, Total Contributions			$ 33,800,000
Equity Method Investment, Ownership Percentage	30.00%		30.00%					30.00%
Loss from Equity Method Investments, Unrecorded	$ 200,000	$ 700,000	$ 1,400,000	$ 2,500,000
Equity Method Investment, Summarized Financial Information, Inception-to-date Cumulative Income (Loss)	43,400,000		43,400,000		42,000,000.0
Equity Method Investments	$ 0		0		$ 0	$ 0	$ 0
Suspended Losses			$ 9,600,000