Statements of Operations In Thousands, except Per Share data	3 Months Ended	12 Months Ended
Sep. 30, 2011 USD ($)	Jun. 30, 2011 USD ($)	Mar. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Sep. 30, 2010 USD ($)	Jun. 30, 2010 USD ($)	Mar. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)	Sep. 30, 2011 USD ($)	Sep. 30, 2010 USD ($)	Sep. 30, 2009 USD ($)
REVENUES
Proceeds from sales of gold	$ 64,310	$ 56,886	$ 53,427	$ 56,073	$ 52,845	$ 42,780	$ 37,685	$ 37,288	$ 230,696	$ 170,598	$ 108,235
Cost of gold sold to pay expenses	(38,013)	(36,240)	(36,035)	(37,288)	(38,858)	(30,894)	(27,664)	(27,348)	(147,576)	(124,764)	(93,494)
Gain on gold sold to pay expenses	26,297	20,646	17,392	18,785	13,987	11,886	10,021	9,940	83,120	45,834	14,741
Gain on gold distributed for the redemption of Shares	3,465,121	1,194,268	1,676,026	1,160,478	724,932	53,934	315,102	245,452	7,495,893	1,339,420	493,732
Total Gain/(loss) on gold	3,491,418	1,214,914	1,693,418	1,179,263	738,919	65,820	325,123	255,392	7,579,013	1,385,254	508,473
EXPENSES
Custody fees	11,240	9,587	8,881	9,346	8,422	7,612	6,452	6,544	39,054	29,030	18,863
Trustee fees	504	499	493	504	504	499	493	504	2,000	2,000	2,000
Sponsor fees	25,792	21,946	20,321	21,458	19,349	17,461	14,606	14,833	89,517	66,249	41,946
Marketing agent fees	25,792	21,946	20,321	21,458	19,349	17,461	14,606	14,833	89,517	66,249	41,946
Other expenses	5,454	4,546	4,172	4,472	3,989	3,622	2,959	3,024	18,644	13,594	8,855
Total expenses	68,782	58,524	54,188	57,238	51,613	46,655	39,116	39,738	238,732	177,122	113,610
Net gain/(loss) from operations	$ 3,422,636	$ 1,156,390	$ 1,639,230	$ 1,122,025	$ 687,306	$ 19,165	$ 286,007	$ 215,654	$ 7,340,281	$ 1,208,132	$ 394,863
Net gain/(loss) per share	$ 8.32	$ 2.89	$ 4.04	$ 2.64	$ 1.61	$ 0.05	$ 0.78	$ 0.59	$ 17.87	$ 3.10	$ 1.24
Weighted average number of shares (000's)	411,484	399,736	406,074	425,404	427,237	400,502	365,749	365,974	410,730	389,968	319,348

The cost of gold sold for the payment of the Trust's expenses which impacts the gain or loss from operations.

Name:	gld_CostOfGoldSoldToPayExpensesImpactOnOperations
Namespace Prefix:	gld
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Total realized gain or loss on the sale and distribution of gold.

+ Details

Name:	gld_GainLossOnGold
Namespace Prefix:	gld
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Realized gain or loss on gold distributed for the redemption of shares.

+ Details

Name:	gld_GainLossOnGoldDistributedForRedemptionOfShares
Namespace Prefix:	gld
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Proceeds from the sale of gold for the payment of the Trust's expenses.

+ Details

Name:	gld_ProceedsFromSalesOfGold
Namespace Prefix:	gld
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Those fees charged for services related to holding, advising, and managing customer investment assets. These account fees usually charged annually or semi-annually, on a per security basis, for the costs of services.

+ Details

Name:	us-gaap_CustodyFees
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of net income or loss for the period per each share of common stock outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 21

-Article 9

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 36, 37, 38

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 20

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 18

-Article 7

+ Details

Name:	us-gaap_EarningsPerShareBasic
Namespace Prefix:	us-gaap
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

+ Details

Name:	us-gaap_GrossProfit
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Expenditures for planning and executing the conception, pricing, promotion, and distribution of ideas, goods, and services. Costs of public relations and corporate promotions are typically considered to be marketing costs.

+ Details

Name:	us-gaap_MarketingExpense
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

+ Details

Name:	us-gaap_OperatingExpenses
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_OperatingExpensesAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents a sum total of expenses not separately reflected on the income statement for the period.

+ Details

Name:	us-gaap_OtherExpenses
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph A1, A4, A5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 5

-Subparagraph b

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 29

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph a

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(1)

+ Details

Name:	us-gaap_ProfitLoss
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_RevenuesAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fees paid to advisors who provide certain management support and administrative oversight services including the organization and sale of stock, investment funds, limited partnerships and mutual funds.

+ Details

Name:	us-gaap_SponsorFees
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Fees charged annually for the professional services of a trustee, usually quoted as a percentage of the funds being managed. An offshore trust must have a Trustee who will administer the assets in the trust for the Beneficiaries. The fee for appointing an offshore Trustee is included in the trust price.

+ Details

Name:	us-gaap_TrusteeFees
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of [basic] shares, after adjustment for contingently issuable shares and other shares not deemed outstanding, determined by relating the portion of time within a reporting period that common shares have been outstanding to the total time in that period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 171

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 40

-Subparagraph a

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 8

+ Details

Name:	us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration