Additional trust expenses paid by sponsor.

No definition available.

Name:	etcg_AdditionalTrustExpensesPaidBySponsor
Namespace Prefix:	etcg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Common Stock Value, Shares Authorized.

+ References

No definition available.

+ Details

Name:	etcg_CommonStockValueSharesAuthorized
Namespace Prefix:	etcg_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of incidental rights distributed in payment of sponsors fee.

+ References

No definition available.

+ Details

Name:	etcg_NumberOfIncidentalRightsDistributedInPaymentOfSponsorsFee
Namespace Prefix:	etcg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of incidental rights held.

+ References

No definition available.

+ Details

Name:	etcg_NumberOfIncidentalRightsHeld
Namespace Prefix:	etcg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of managers fee.

+ References

No definition available.

+ Details

Name:	etcg_PercentageOfManagersFee
Namespace Prefix:	etcg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Value of shares purchased.

+ References

No definition available.

+ Details

Name:	etcg_ValueOfSharesPurchased
Namespace Prefix:	etcg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount for accounts payable to related parties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

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 210.9-03.15(5))
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.17)
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

+ Details

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

- Definition

Number of common stock held in a trust that has been set up specifically to accumulate stock for the sole purpose of distribution to participating employees but not yet earned.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 25
-Paragraph 12
-URI https://asc.fasb.org/extlink&oid=109244457&loc=d3e16701-113920

+ Details

Name:	us-gaap_CommonStockSharesHeldInEmployeeTrustShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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

- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

+ Details

Name:	us-gaap_RelatedPartyTransactionAmountsOfTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

+ Details

Name:	us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Identify the stated interest rate per the agreement, for example, leasing and debt arrangements between related parties.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionRate
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Details

Name:	srt_OwnershipAxis=etcg_CoinbaseIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

Related Parties - Additional Information (Detail)			3 Months Ended		6 Months Ended		12 Months Ended
Related Parties - Additional Information (Detail)	Apr. 01, 2022	Mar. 02, 2022 USD ($)	Jun. 30, 2022 USD ($) Right shares	Jun. 30, 2021 USD ($) Right	Jun. 30, 2022 USD ($) Right shares	Jun. 30, 2021 USD ($) Right	Jun. 30, 2022 USD ($) Right shares	Dec. 31, 2021 USD ($) Right shares	Jun. 21, 2021 USD ($)
Related Party Transaction [Line Items]
Shares of the Trust, held by related parties \| shares			3,271,674		3,271,674		3,271,674	3,271,674
Number of Incidental Rights held \| Right			0		0		0	0
Number of Incidental Rights distributed \| Right			0	0	0	0
Related party sponsor fee percentage					2.50%
Percentage of manager's fee	3.00%				2.50%
Sponsor's Fees incurred			$ 1,964,068	$ 5,053,490	$ 4,767,539	$ 6,014,091
Accrued and unpaid Sponsor's Fees			0		0		$ 0	$ 0
Additional trust expenses paid by sponsor			$ 0	$ 0	$ 0	$ 0
Sponsor's Parent \| Coinbase Inc
Related Party Transaction [Line Items]
Percentage of minority interest owned			1.00%		1.00%		1.00%
Sponsor
Related Party Transaction [Line Items]
Related party maximum transaction in a fiscal year					$ 600,000
Non Sponsor Paid Expenses
Related Party Transaction [Line Items]
Related party maximum transaction in a fiscal year					$ 600,000
D C G
Related Party Transaction [Line Items]
Value of shares purchased							$ 45,300,000
D C G \| Maximum
Related Party Transaction [Line Items]
Common Stock Value, Shares Authorized		$ 50,000,000							$ 50,000,000
Value of shares purchased		$ 200,000,000