Segment and Related Information - Operating Results by Segment (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Revenue	$ 2,087	$ 1,846	$ 6,209	$ 5,575
Operating Profit	1,083	944	3,317	2,960
Amortization of intangibles from acquisitions	21	32	74	94
Gain on disposition	3	8	5	16
Lease impairment			3
Operating Segments
Segment Reporting Information [Line Items]
Operating Profit	1,172	980	3,579	3,088
Operating Segments \| Ratings
Segment Reporting Information [Line Items]
Revenue	1,017	894	3,107	2,725
Operating Profit	644	544	2,054	1,758
Impairment charges				5
Amortization of intangibles from acquisitions	2	3	8	5
Operating Segments \| Market Intelligence
Segment Reporting Information [Line Items]
Revenue	570	530	1,664	1,565
Operating Profit	187	164	533	469
Amortization of intangibles from acquisitions	16	19	49	58
Gain on disposition		4	2	12
Employee severance charges				2
Operating Segments \| Platts
Segment Reporting Information [Line Items]
Revenue	239	222	700	654
Operating Profit	128	121	392	357
Amortization of intangibles from acquisitions	2	2	6	7
Operating Segments \| Indices
Segment Reporting Information [Line Items]
Revenue	298	234	846	733
Operating Profit	213	151	600	504
Amortization of intangibles from acquisitions	1	1	4	4
Intersegment Elimination
Segment Reporting Information [Line Items]
Revenue	(37)	(34)	(108)	(102)
Corporate Unallocated
Segment Reporting Information [Line Items]
Operating Profit	(89)	(36)	(262)	(128)
Amortization of intangibles from acquisitions		7	7	20
Gain on disposition		4	3	4
Employee severance charges				10
Lease impairment			3
Retention related expenses		$ 2	2	$ 10
Corporate Unallocated \| IHS Markit
Segment Reporting Information [Line Items]
Acquisition-related costs	$ 54		$ 153

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

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The net result for the period of deducting operating expenses from operating revenues.

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Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

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