Significant Accounting Policies - Additional Information (Details)	2 Months Ended
	Sep. 30, 2024 USD ($)
Accounting Policies [Line Items]
Sponsor's fee rate	0.19%
Sponsor's fee	$ 10,129	[1]
Less waiver and reimbursement	10,129	[1]
Sponsor's fee payable	$ 0	[1]
Franklin Ethereum ETF [Member]
Accounting Policies [Line Items]
Sponsor's fee rate	0.19%
Sponsor's fee	$ 10,129	[1]
Less waiver and reimbursement	10,129
Sponsor's fee payable	0	[1]
Sponsor [Member] | Ordinary Fees And Expenses Incurred By The Fund [Member]
Accounting Policies [Line Items]
Amount of expenses agreed to be borne by the counterparty	500,000
Initial value of the funds assets on the basis of which fees is determined	10,000,000,000
Other non recurring expenses threshold limit above which shall be borne by the fund	500,000
Sponsor [Member] | Ordinary Fees And Expenses Incurred By The Fund [Member] | Franklin Ethereum ETF [Member]
Accounting Policies [Line Items]
Amount of expenses agreed to be borne by the counterparty	500,000
Initial value of the funds assets on the basis of which fees is determined	10,000,000,000
Other non recurring expenses threshold limit above which shall be borne by the fund	500,000
Sponsor [Member] | Ordinary Fees And Expenses Incurred By The Fund [Member] | Minimum [Member]
Accounting Policies [Line Items]
Amount of expenses agreed to be borne by the counterparty	500,000
Sponsor [Member] | Ordinary Fees And Expenses Incurred By The Fund [Member] | Minimum [Member] | Franklin Ethereum ETF [Member]
Accounting Policies [Line Items]
Amount of expenses agreed to be borne by the counterparty	$ 500,000

[1] No comparative period presented as the Fund’s operations commenced on July 23, 2024.