The equity interest of other holders in equity method investment.

No definition available.

Name:	ctgo_EquityMethodInvestmentOwnershipPercentageByOtherOwner
Namespace Prefix:	ctgo_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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
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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
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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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ 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://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

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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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
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-Paragraph 1
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 25
-Subparagraph (a)
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-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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
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Note 8 - Investment in Peak Gold, LLC (Details Textual) - USD ($)	12 Months Ended		66 Months Ended	78 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Sep. 29, 2020	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015	Jan. 08, 2015	Jun. 30, 2014
Equity Method Investments
The Joint Venture Company [Member]
Equity Method Investment, Aggregate Cost	15,700,000			$ 15,700,000									$ 1,400,000
Equity Method Investment, Total Contributions	$ 15,700,000
Equity Method Investment, Ownership Percentage	30.00%			30.00%	30.00%	30.00%	30.00%
Loss from Equity Method Investments, Unrecorded	$ 4,000,000	3,200,000
Equity Method Investment, Summarized Financial Information, Inception-to-date Cumulative Income (Loss)	38,700,000	34,700,000	34,700,000	$ 38,700,000
Payments to Acquire Interest in Joint Venture			14,300,000
Equity Method Investments	$ 0	$ 0	$ 0	0		$ 0
Suspended Losses				$ 23,000,000
The Joint Venture Company [Member] \| KG Mining [Member]
Equity Method Investment, Ownership Percentage by Other Owner						70.00%