Condensed Consolidating Financial Statements - Balance Sheet (Details) - USD ($) $ in Millions	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 3,148		$ 2,866
Restricted cash	20		20
Accounts receivable, net of allowance for doubtful accounts	1,427		1,577
Intercompany receivable	0		0
Prepaid and other current assets	246		249
Total current assets	4,841		4,712
Property and equipment, net of accumulated depreciation	298		320
Right of use assets	610		676
Goodwill	3,715		3,575
Other intangible assets, net	1,376		1,424
Investments in subsidiaries	0		0
Intercompany loans receivable	0		0
Other non-current assets	612		641
Total assets	11,452		11,348
Current liabilities:
Accounts payable	186		190
Intercompany payable	0		0
Accrued compensation and contributions to retirement plans	392		446
Income taxes currently payable	79		68
Unearned revenue	1,720		1,928
Other current liabilities	438		461
Total current liabilities	2,815		3,093
Long-term debt	4,110		3,948
Lease liabilities — non-current	563		620
Intercompany loans payable	0		0
Pension and other postretirement benefits	262		259
Other non-current liabilities	693		624
Total liabilities	8,443		8,544
Redeemable noncontrolling interest	2,511		2,268
Equity:
Common stock	294		294
Additional paid-in capital	917		903
Retained income	13,368		12,205
Accumulated other comprehensive loss	(677)		(624)
Less: common stock in treasury	(13,460)		(12,299)
Total equity — controlling interests	442		479
Total equity - noncontrolling interests	56		57
Total equity	498	$ 268	536	$ 402	$ 570	$ 684
Total liabilities and equity	11,452		11,348
Eliminations
Current assets:
Cash and cash equivalents	0		0
Restricted cash	0		0
Accounts receivable, net of allowance for doubtful accounts	0		0
Intercompany receivable	(8,839)		(7,513)
Prepaid and other current assets	0		0
Total current assets	(8,839)		(7,513)
Property and equipment, net of accumulated depreciation	0		0
Right of use assets	0		0
Goodwill	7		9
Other intangible assets, net	0		0
Investments in subsidiaries	(20,973)		(20,228)
Intercompany loans receivable	(1,124)		(1,246)
Other non-current assets	(1)		(1)
Total assets	(30,930)		(28,979)
Current liabilities:
Accounts payable	0		0
Intercompany payable	(8,839)		(7,513)
Accrued compensation and contributions to retirement plans	0		0
Income taxes currently payable	0		0
Unearned revenue	0		0
Other current liabilities	0		0
Total current liabilities	(8,839)		(7,513)
Long-term debt	0		0
Lease liabilities — non-current	0		0
Intercompany loans payable	(1,124)		(1,246)
Pension and other postretirement benefits	0		0
Other non-current liabilities	0		(1)
Total liabilities	(9,963)		(8,760)
Redeemable noncontrolling interest	2,511		2,268
Equity:
Common stock	(2,375)		(2,377)
Additional paid-in capital	(9,361)		(9,203)
Retained income	(11,842)		(11,010)
Accumulated other comprehensive loss	46		48
Less: common stock in treasury	0		0
Total equity — controlling interests	(23,532)		(22,542)
Total equity - noncontrolling interests	54		55
Total equity	(23,478)		(22,487)
Total liabilities and equity	(30,930)		(28,979)
S&P Global Inc. | Reportable Legal Entities
Current assets:
Cash and cash equivalents	1,818		1,130
Restricted cash	0		0
Accounts receivable, net of allowance for doubtful accounts	216		229
Intercompany receivable	652		675
Prepaid and other current assets	104		102
Total current assets	2,790		2,136
Property and equipment, net of accumulated depreciation	188		204
Right of use assets	364		402
Goodwill	283		283
Other intangible assets, net	0		0
Investments in subsidiaries	12,739		12,134
Intercompany loans receivable	17		17
Other non-current assets	238		281
Total assets	16,619		15,457
Current liabilities:
Accounts payable	77		80
Intercompany payable	7,633		6,288
Accrued compensation and contributions to retirement plans	138		148
Income taxes currently payable	16		7
Unearned revenue	308		297
Other current liabilities	171		187
Total current liabilities	8,343		7,007
Long-term debt	4,110		3,948
Lease liabilities — non-current	351		383
Intercompany loans payable	0		0
Pension and other postretirement benefits	174		178
Other non-current liabilities	204		171
Total liabilities	13,182		11,687
Redeemable noncontrolling interest	0		0
Equity:
Common stock	294		294
Additional paid-in capital	103		112
Retained income	16,722		15,836
Accumulated other comprehensive loss	(224)		(175)
Less: common stock in treasury	(13,458)		(12,297)
Total equity — controlling interests	3,437		3,770
Total equity - noncontrolling interests	0		0
Total equity	3,437		3,770
Total liabilities and equity	16,619		15,457
Standard & Poor's Financial Services LLC | Reportable Legal Entities
Current assets:
Cash and cash equivalents	0		0
Restricted cash	0		0
Accounts receivable, net of allowance for doubtful accounts	209		148
Intercompany receivable	3,485		2,855
Prepaid and other current assets	(1)		2
Total current assets	3,693		3,005
Property and equipment, net of accumulated depreciation	0		0
Right of use assets	1		1
Goodwill	0		0
Other intangible assets, net	0		0
Investments in subsidiaries	6		6
Intercompany loans receivable	0		0
Other non-current assets	33		37
Total assets	3,733		3,049
Current liabilities:
Accounts payable	10		11
Intercompany payable	53		27
Accrued compensation and contributions to retirement plans	50		61
Income taxes currently payable	0		0
Unearned revenue	245		243
Other current liabilities	13		18
Total current liabilities	371		360
Long-term debt	0		0
Lease liabilities — non-current	1		1
Intercompany loans payable	0		0
Pension and other postretirement benefits	0		0
Other non-current liabilities	76		81
Total liabilities	448		442
Redeemable noncontrolling interest	0		0
Equity:
Common stock	0		0
Additional paid-in capital	642		632
Retained income	2,643		1,975
Accumulated other comprehensive loss	0		0
Less: common stock in treasury	0		0
Total equity — controlling interests	3,285		2,607
Total equity - noncontrolling interests	0		0
Total equity	3,285		2,607
Total liabilities and equity	3,733		3,049
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	1,330		1,736
Restricted cash	20		20
Accounts receivable, net of allowance for doubtful accounts	1,002		1,200
Intercompany receivable	4,702		3,983
Prepaid and other current assets	143		145
Total current assets	7,197		7,084
Property and equipment, net of accumulated depreciation	110		116
Right of use assets	245		273
Goodwill	3,425		3,283
Other intangible assets, net	1,376		1,424
Investments in subsidiaries	8,228		8,088
Intercompany loans receivable	1,107		1,229
Other non-current assets	342		324
Total assets	22,030		21,821
Current liabilities:
Accounts payable	99		99
Intercompany payable	1,153		1,198
Accrued compensation and contributions to retirement plans	204		237
Income taxes currently payable	63		61
Unearned revenue	1,167		1,388
Other current liabilities	254		256
Total current liabilities	2,940		3,239
Long-term debt	0		0
Lease liabilities — non-current	211		236
Intercompany loans payable	1,124		1,246
Pension and other postretirement benefits	88		81
Other non-current liabilities	413		373
Total liabilities	4,776		5,175
Redeemable noncontrolling interest	0		0
Equity:
Common stock	2,375		2,377
Additional paid-in capital	9,533		9,362
Retained income	5,845		5,404
Accumulated other comprehensive loss	(499)		(497)
Less: common stock in treasury	(2)		(2)
Total equity — controlling interests	17,252		16,644
Total equity - noncontrolling interests	2		2
Total equity	17,254		16,646
Total liabilities and equity	$ 22,030		$ 21,821