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- Definition

The carrying value of the amount of fixed rate debt outstanding at the balance sheet date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The number of additional percentage points added to the reference rate as a facility fee on the line of credit.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of other than borrowings in the currency of the country of domicile, identification of the currency in which borrowings are made.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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Period Type:	duration

- Definition

Maximum borrowing capacity to which the credit facility was expanded per the terms of the agreement of the reporting entity.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Maximum borrowing capacity to which the credit facility may be expanded per the terms of the agreement, at the option of the reporting entity.

+ References

No definition available.

+ Details

Name:	spg_LineOfCreditFacilityMaximumBorrowingCapacityOptionalExpanded
Namespace Prefix:	spg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the number of credit facilities available to the entity.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of pools of cross-defaulted and cross-collateralized mortgages encumbering the entity's properties.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
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- Definition

The total number of properties pledged as collateral for cross defaulted and cross collateralized mortgages.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
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- Definition

The number of real estate properties in which additional interests were acquired during the period.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.13,16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Balance Type:	na
Period Type:	instant

- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Balance Type:	credit
Period Type:	instant

- Definition

Average amount borrowed under the credit facility during the period.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Maximum amount borrowed under the credit facility at any time during the period.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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- Definition

Indicates the number of mortgages under each classification.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule IV)

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-29.3)

-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule IV

-Article 5

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 29

-Paragraph 3

-Article 12

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- Definition

The number of real estate properties owned as of the balance sheet date.

+ References

No definition available.

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Debt (Details) (USD $)	3 Months Ended	12 Months Ended	0 Months Ended
Debt (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Jan. 15, 2015 property	Mar. 02, 2015
Debt
Total Mortgages and Other Indebtedness	$ 21,694,055,000us-gaap_DebtAndCapitalLeaseObligations	$ 20,852,993,000us-gaap_DebtAndCapitalLeaseObligations
Fair value of debt
Carrying value of fixed-rate mortgages and unsecured indebtedness	19,300,000,000spg_FixedRateDebt	19,000,000,000spg_FixedRateDebt
Fair value of fixed-rate mortgages and unsecured indebtedness	20,932,000,000us-gaap_LongTermDebtFairValue	20,558,000,000us-gaap_LongTermDebtFairValue
Weighted average discount rates assumed in calculation of fair value for fixed-rate mortgages (as a percent)	2.69%us-gaap_FairValueInputsDiscountRate	3.02%us-gaap_FairValueInputsDiscountRate
Jersey Gardens and University Park Village
Debt
Number of properties in which interest is acquired			2
Mortgage Maturing November 1, 2020 \| Jersey Gardens (The Mills at Jersey Gardens)
Debt
Total Mortgages and Other Indebtedness			350,000,000
Interest rate on debt (as a percent)			3.83%
Mortgage Maturing May 1, 2028 \| University Park Village
Debt
Total Mortgages and Other Indebtedness			55,000,000
Interest rate on debt (as a percent)			3.85%
Unsecured Debt \| Senior unsecured notes \| Operating Partnership
Debt
Total Mortgages and Other Indebtedness	13,300,000,000
Unsecured Debt \| Credit Facility and the Supplemental Facility \| Operating Partnership
Debt
Available borrowing capacity	5,200,000,000
Maximum amount outstanding during period	1,500,000,000
Credit facility, weighted average amount outstanding	1,100,000,000
Letters of credit outstanding	36,900,000
Number of credit facilities	2
Unsecured Debt \| Credit Facility \| Operating Partnership
Debt
Credit facility, amount outstanding	1,000,000,000
Maximum borrowing capacity	4,000,000,000
Optional expanded maximum borrowing capacity	5,000,000,000
Additional facility fee (as a percent)	0.10%
Unsecured Debt \| Credit Facility \| Operating Partnership \| Euro
Debt
Credit facility, amount outstanding	753,800,000
Unsecured Debt \| Credit Facility \| Operating Partnership \| Yen
Debt
Credit facility, amount outstanding	185,500,000
Unsecured Debt \| Credit Facility \| Maximum \| Operating Partnership
Debt
Percentage of borrowings in currencies other than the U.S. Dollar	75.00%
Unsecured Debt \| Credit Facility \| LIBOR \| Operating Partnership
Debt
Reference rate	LIBOR
Interest added to reference rate (as a percent)	0.80%
Unsecured Debt \| Supplemental Facility \| Operating Partnership
Debt
Maximum borrowing capacity				2,000,000,000
Unsecured Debt \| Amended Supplemental Facility \| Operating Partnership
Debt
Maximum borrowing capacity				2,750,000,000
Optional expanded maximum borrowing capacity				3,500,000,000
Additional facility fee (as a percent)				0.10%
Unsecured Debt \| Amended Supplemental Facility \| LIBOR \| Operating Partnership
Debt
Reference rate				LIBOR
Interest added to reference rate (as a percent)				0.80%
Unsecured Debt \| Term loan
Debt
Total Mortgages and Other Indebtedness	240,000,000
Unsecured Debt \| Commercial Paper \| Operating Partnership
Debt
Credit facility, amount outstanding	471,300,000
Maximum borrowing capacity				500,000,000
Expanded maximum borrowing capacity				1,000,000,000
Unsecured Debt \| Commercial Paper \| Operating Partnership \| USD
Debt
Credit facility, amount outstanding	285,000,000
Weighted average interest rate (as a percent)	0.20%
Unsecured Debt \| Commercial Paper \| Operating Partnership \| Euro
Debt
Credit facility, amount outstanding	186,300,000
Weighted average interest rate (as a percent)	0.08%
Secured Debt \| Mortgages
Debt
Total Mortgages and Other Indebtedness	$ 6,600,000,000	$ 6,200,000,000
Debt covenants
Number of non-recourse mortgage notes under which the Company and subsidiaries are borrowers	40
Number of properties secured by non-recourse mortgage notes	54
Number of cross-defaulted and cross-collateralized mortgage pools	5
Total number of properties pledged as collateral for cross defaulted and cross collateralized mortgages	21