Condensed Consolidating Financial Statements - Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,403	$ 1,917
Restricted cash	33	41
Accounts receivable, net of allowance for doubtful accounts	1,539	1,449
Intercompany receivable	0	0
Prepaid and other current assets	207	197
Total current assets	3,182	3,604
Property and equipment, net of accumulated depreciation	268	270
Right of use assets	675	0
Goodwill	3,533	3,535
Other intangible assets, net	1,492	1,524
Investments in subsidiaries	0	0
Intercompany loans receivable	0	0
Other non-current assets	570	525
Total assets	9,720	9,458
Current liabilities:
Accounts payable	217	211
Intercompany payable	0	0
Accrued compensation and contributions to retirement plans	200	354
Income taxes currently payable	134	72
Unearned revenue	1,689	1,641
Other current liabilities	415	351
Total current liabilities	2,655	2,629
Long-term debt	3,663	3,662
Lease liabilities — non-current	617	0
Intercompany loans payable	0	0
Pension and other postretirement benefits	227	229
Other non-current liabilities	523	634
Total liabilities	7,685	7,154
Redeemable noncontrolling interest	1,647	1,620
Equity:
Common stock	294	294
Additional paid-in capital	772	833
Retained income	11,532	11,284
Accumulated other comprehensive loss	(633)	(742)
Less: common stock in treasury	(11,638)	(11,041)
Total equity — controlling interests	327	628
Total equity - noncontrolling interests	61	56
Total equity	388	684	$ 65	$ 768
Total liabilities and equity	9,720	9,458
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	(7,957)	(5,561)
Prepaid and other current assets	0	0
Total current assets	(7,957)	(5,561)
Property and equipment, net of accumulated depreciation	0	0
Right of use assets	0	0
Goodwill	9	9
Other intangible assets, net	0	0
Investments in subsidiaries	(18,384)	(16,635)
Intercompany loans receivable	(1,737)	(1,773)
Other non-current assets	0	0
Total assets	(28,069)	(23,960)
Current liabilities:
Accounts payable	0	0
Intercompany payable	(7,956)	(5,561)
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	(7,956)	(5,561)
Long-term debt	0	0
Lease liabilities — non-current	0	0
Intercompany loans payable	(1,737)	(1,773)
Pension and other postretirement benefits	0	0
Other non-current liabilities	0	0
Total liabilities	(9,693)	(7,334)
Redeemable noncontrolling interest	1,647	1,620
Equity:
Common stock	(2,372)	(2,279)
Additional paid-in capital	(9,640)	(9,641)
Retained income	(8,125)	(6,439)
Accumulated other comprehensive loss	44	46
Less: common stock in treasury	10	12
Total equity — controlling interests	(20,083)	(18,301)
Total equity - noncontrolling interests	60	55
Total equity	(20,023)	(18,246)
Total liabilities and equity	(28,069)	(23,960)
S&P Global Inc. | Reportable Legal Entities
Current assets:
Cash and cash equivalents	146	694
Restricted cash	0	0
Accounts receivable, net of allowance for doubtful accounts	240	163
Intercompany receivable	1,643	550
Prepaid and other current assets	49	58
Total current assets	2,078	1,465
Property and equipment, net of accumulated depreciation	196	192
Right of use assets	419	0
Goodwill	261	261
Other intangible assets, net	0	0
Investments in subsidiaries	10,255	8,599
Intercompany loans receivable	131	130
Other non-current assets	203	194
Total assets	13,543	10,841
Current liabilities:
Accounts payable	83	89
Intercompany payable	5,690	4,453
Accrued compensation and contributions to retirement plans	86	125
Income taxes currently payable	53	1
Unearned revenue	249	240
Other current liabilities	183	180
Total current liabilities	6,344	5,088
Long-term debt	3,663	3,662
Lease liabilities — non-current	390	0
Intercompany loans payable	116	114
Pension and other postretirement benefits	161	162
Other non-current liabilities	132	166
Total liabilities	10,806	9,192
Redeemable noncontrolling interest	0	0
Equity:
Common stock	294	294
Additional paid-in capital	4	72
Retained income	14,292	12,622
Accumulated other comprehensive loss	(216)	(299)
Less: common stock in treasury	(11,637)	(11,040)
Total equity — controlling interests	2,737	1,649
Total equity - noncontrolling interests	0	0
Total equity	2,737	1,649
Total liabilities and equity	13,543	10,841
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	208	109
Intercompany receivable	2,896	2,138
Prepaid and other current assets	4	3
Total current assets	3,108	2,250
Property and equipment, net of accumulated depreciation	0	0
Right of use assets	1	0
Goodwill	0	0
Other intangible assets, net	0	0
Investments in subsidiaries	6	6
Intercompany loans receivable	0	0
Other non-current assets	47	45
Total assets	3,162	2,301
Current liabilities:
Accounts payable	16	15
Intercompany payable	897	32
Accrued compensation and contributions to retirement plans	13	33
Income taxes currently payable	0	0
Unearned revenue	257	235
Other current liabilities	15	16
Total current liabilities	1,198	331
Long-term debt	0	0
Lease liabilities — non-current	1	0
Intercompany loans payable	0	0
Pension and other postretirement benefits	0	0
Other non-current liabilities	72	75
Total liabilities	1,271	406
Redeemable noncontrolling interest	0	0
Equity:
Common stock	0	0
Additional paid-in capital	619	618
Retained income	1,272	1,277
Accumulated other comprehensive loss	0	0
Less: common stock in treasury	0	0
Total equity — controlling interests	1,891	1,895
Total equity - noncontrolling interests	0	0
Total equity	1,891	1,895
Total liabilities and equity	3,162	2,301
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	1,257	1,223
Restricted cash	33	41
Accounts receivable, net of allowance for doubtful accounts	1,091	1,177
Intercompany receivable	3,418	2,873
Prepaid and other current assets	154	136
Total current assets	5,953	5,450
Property and equipment, net of accumulated depreciation	72	78
Right of use assets	255	0
Goodwill	3,263	3,265
Other intangible assets, net	1,492	1,524
Investments in subsidiaries	8,123	8,030
Intercompany loans receivable	1,606	1,643
Other non-current assets	320	286
Total assets	21,084	20,276
Current liabilities:
Accounts payable	118	107
Intercompany payable	1,369	1,076
Accrued compensation and contributions to retirement plans	101	196
Income taxes currently payable	81	71
Unearned revenue	1,183	1,166
Other current liabilities	217	155
Total current liabilities	3,069	2,771
Long-term debt	0	0
Lease liabilities — non-current	226	0
Intercompany loans payable	1,621	1,659
Pension and other postretirement benefits	66	67
Other non-current liabilities	319	393
Total liabilities	5,301	4,890
Redeemable noncontrolling interest	0	0
Equity:
Common stock	2,372	2,279
Additional paid-in capital	9,789	9,784
Retained income	4,093	3,824
Accumulated other comprehensive loss	(461)	(489)
Less: common stock in treasury	(11)	(13)
Total equity — controlling interests	15,782	15,385
Total equity - noncontrolling interests	1	1
Total equity	15,783	15,386
Total liabilities and equity	$ 21,084	$ 20,276