Indebtedness to cash flow ratio

No definition available.

Name:	spgi_IndebtednessToCashFlow
Namespace Prefix:	spgi_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

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

+ References

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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

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Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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

+ Details

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Namespace Prefix:	us-gaap_
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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

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

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19)(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: 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(a)(16)(a)(1))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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(13))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Period Type:	instant

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Debt - Narrative (Details)		9 Months Ended
Debt - Narrative (Details)	Jun. 30, 2017	Sep. 30, 2018 USD ($)	Jun. 01, 2018 USD ($)	May 17, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Aug. 18, 2015 USD ($)
Debt Instrument [Line Items]
Long-term debt, fair value		$ 3,800,000,000			$ 3,800,000,000
Five-Year Credit Agreement \| Maximum
Debt Instrument [Line Items]
Indebtedness to cash flow (not greater than)		4
Five-Year Credit Agreement \| Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 1,200,000,000.0
Credit facility, term (in years)	5 years
Commitment fee		0.125%
Five-Year Credit Agreement \| Revolving Credit Facility \| Minimum
Debt Instrument [Line Items]
Commitment fee		0.08%
Five-Year Credit Agreement \| Revolving Credit Facility \| Maximum
Debt Instrument [Line Items]
Commitment fee		0.175%
Five-Year Credit Agreement \| Commercial paper
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 1,200,000,000.0
Short-term debt		$ 0			$ 0
Senior Notes
Debt Instrument [Line Items]
Debt issued							$ 2,000,000,000.0
Senior Notes \| 4.5% Senior Notes, due 2048
Debt Instrument [Line Items]
Debt issued				$ 500,000,000
Stated interest rate (as a percent)		4.50%
Senior Notes \| 2.5% Senior Notes, due 2018
Debt Instrument [Line Items]
Debt issued			$ 400,000,000
Stated interest rate (as a percent)		2.50%