Note 2 - Significant Accounting Policies (Details Textual) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Mar. 31, 2025 USD ($)	Mar. 31, 2024 USD ($)	Mar. 31, 2025 USD ($) shares	Mar. 31, 2024 USD ($)	Sep. 30, 2024 USD ($)
Fair Value Assets and Liabilities, Transfers Between Level One, Level Two and Level Three			$ 0		$ 0
Percentage of Gold Held as Good Delivery Gold Bars	100.00%		100.00%
Maximum Number of Business Days to Transfer Ownership of Gold			1 day
Minimum Block of Shares Issued Redeemed Against Gold (in shares) \| shares			100,000
Gain (Loss) on Investments	$ 14,352,151	$ 3,976,266	$ 13,823,510	$ 9,302,781
Gain (Loss) on Sale of Trust Assets to Pay Expenses	24,129	9,826	46,435	17,044
Net Realized Gain Loss From Gold Distributed For The Redemption Of Shares	2,484,386	993,325	4,637,254	1,502,685
Unrealized Gain (Loss) on Investments	11,843,636	$ 2,973,115	9,139,821	$ 7,783,052
Liability for Uncertainty in Income Taxes, Current	$ 0		$ 0		$ 0
Income Tax Examination, Description			There were no examinations in progress at period end.
Number of Income Tax Examinations In Progress			0

The amount of transfers between level 1, level 2 and level 3 of fair value if assets and liabilities.

No definition available.

Name:	gld_FairValueAssetsAndLiabilitiesTransfersBetweenLevelOneLevelTwoAndLevelThree
Namespace Prefix:	gld_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The maximum number of days to transfer ownership of gold.

+ References

No definition available.

+ Details

Name:	gld_MaximumNumberOfBusinessDaysToTransferOwnershipOfGold
Namespace Prefix:	gld_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The minimum block of shares issued for redemption against gold.

+ References

No definition available.

+ Details

Name:	gld_MinimumBlockOfSharesIssuedRedeemedAgainstGold
Namespace Prefix:	gld_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Net realized gain loss from gold distributed for the redemption of shares.

+ References

No definition available.

+ Details

Name:	gld_NetRealizedGainLossFromGoldDistributedForTheRedemptionOfShares
Namespace Prefix:	gld_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of income tax examinations in progress.

+ References

No definition available.

+ Details

Name:	gld_NumberOfIncomeTaxExaminationsInProgress
Namespace Prefix:	gld_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of gold held in the form of good delivery gold bars.

+ References

No definition available.

+ Details

Name:	gld_PercentageOfGoldHeldAsGoodDeliveryGoldBars
Namespace Prefix:	gld_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of realized and unrealized gain (loss) on investment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(9)(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 3: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

+ Details

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

- Definition

Gain (loss) related to the sale of trust assets (includes, but is not limited to, gold and silver) to pay trust expenses.

+ References

No definition available.

+ Details

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

- Definition

A brief description of status of the tax examination, significant findings to date, and the entity's position with respect to the findings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15

+ Details

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

- Definition

Amount recognized for uncertainty in income taxes classified as current.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(20))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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

- Definition

Amount of unrealized gain (loss) on investment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

+ Details

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