Condensed Consolidating Financial Statements - Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 2,779	$ 2,392	$ 1,481	$ 2,497
Accounts receivable, net of allowance for doubtful accounts	1,319	1,122
Intercompany receivable	0	0
Prepaid and other current assets	226	157
Total current assets	4,324	3,671
Property and equipment, net of accumulated depreciation	275	271
Goodwill	2,989	2,949	2,882
Other intangible assets, net	1,388	1,506
Investments in subsidiaries	0	0
Intercompany loans receivable	0	0
Other non-current assets	449	272
Total assets	9,425	8,669
Current liabilities:
Accounts payable	195	183
Intercompany payable	0	0
Accrued compensation and contributions to retirement plans	472	409
Short-term debt	399	0
Income taxes currently payable	77	95
Unearned revenue	1,613	1,509
Accrued legal and regulatory settlements	107	56
Other current liabilities	351	359
Total current liabilities	3,214	2,611
Long-term debt	3,170	3,564
Intercompany loans payable	0	0
Pension and other postretirement benefits	244	274
Other non-current liabilities	679	439
Total liabilities	7,307	6,888
Redeemable noncontrolling interest	1,350	1,080
Equity:
Common stock	412	412
Additional paid-in capital	525	502
Retained income	10,025	9,210
Accumulated other comprehensive loss	(649)	(773)
Less: common stock in treasury	(9,602)	(8,701)
Total equity – controlling interests	711	650
Total equity – noncontrolling interests	57	51
Total equity	768	701	243	539
Total liabilities and equity	9,425	8,669
Eliminations
Current assets:
Cash and cash equivalents	0	0	0	0
Accounts receivable, net of allowance for doubtful accounts	0	0
Intercompany receivable	(5,079)	(1,542)
Prepaid and other current assets	0	(1)
Total current assets	(5,079)	(1,543)
Property and equipment, net of accumulated depreciation	0	0
Goodwill	9	9
Other intangible assets, net	0	0
Investments in subsidiaries	(16,397)	(13,970)
Intercompany loans receivable	(1,815)	(1,371)
Other non-current assets	(1)	0
Total assets	(23,283)	(16,875)
Current liabilities:
Accounts payable	0	0
Intercompany payable	(5,079)	(1,541)
Accrued compensation and contributions to retirement plans	0	0
Short-term debt	0
Income taxes currently payable	0	0
Unearned revenue	0	0
Accrued legal and regulatory settlements	0
Other current liabilities	0	0
Total current liabilities	(5,079)	(1,541)
Long-term debt	0	0
Intercompany loans payable	(1,816)	(1,371)
Pension and other postretirement benefits	0	0
Other non-current liabilities	0	(1)
Total liabilities	(6,895)	(2,913)
Redeemable noncontrolling interest	1,350	1,080
Equity:
Common stock	(2,318)	(2,460)
Additional paid-in capital	(9,117)	(10,963)
Retained income	(6,429)	(1,721)
Accumulated other comprehensive loss	46	44
Less: common stock in treasury	23	7
Total equity – controlling interests	(17,795)	(15,093)
Total equity – noncontrolling interests	57	51
Total equity	(17,738)	(15,042)
Total liabilities and equity	(23,283)	(16,875)
S&P Global Inc. | Reportable Legal Entities
Current assets:
Cash and cash equivalents	632	711	167	1,402
Accounts receivable, net of allowance for doubtful accounts	138	138
Intercompany receivable	768	(165)
Prepaid and other current assets	143	77
Total current assets	1,681	761
Property and equipment, net of accumulated depreciation	158	159
Goodwill	261	261
Other intangible assets, net	0	0
Investments in subsidiaries	8,364	5,464
Intercompany loans receivable	116	17
Other non-current assets	215	134
Total assets	10,795	6,796
Current liabilities:
Accounts payable	79	73
Intercompany payable	3,433	1,324
Accrued compensation and contributions to retirement plans	145	129
Short-term debt	399
Income taxes currently payable	2	43
Unearned revenue	293	273
Accrued legal and regulatory settlements	0	2
Other current liabilities	136	163
Total current liabilities	4,487	2,007
Long-term debt	3,170	3,564
Intercompany loans payable	101	11
Pension and other postretirement benefits	180	196
Other non-current liabilities	376	52
Total liabilities	8,314	5,830
Redeemable noncontrolling interest	0	0
Equity:
Common stock	412	412
Additional paid-in capital	(216)	(174)
Retained income	12,156	9,721
Accumulated other comprehensive loss	(269)	(292)
Less: common stock in treasury	(9,602)	(8,701)
Total equity – controlling interests	2,481	966
Total equity – noncontrolling interests	0	0
Total equity	2,481	966
Total liabilities and equity	10,795	6,796
Standard & Poor's Financial Services LLC | Reportable Legal Entities
Current assets:
Cash and cash equivalents	0	0	0	0
Accounts receivable, net of allowance for doubtful accounts	152	131
Intercompany receivable	1,784	837
Prepaid and other current assets	(3)	2
Total current assets	1,933	970
Property and equipment, net of accumulated depreciation	10	1
Goodwill	0	0
Other intangible assets, net	0	0
Investments in subsidiaries	5	680
Intercompany loans receivable	0	0
Other non-current assets	61	24
Total assets	2,009	1,675
Current liabilities:
Accounts payable	23	22
Intercompany payable	492	40
Accrued compensation and contributions to retirement plans	86	69
Short-term debt	0
Income taxes currently payable	0	0
Unearned revenue	193	191
Accrued legal and regulatory settlements	2	3
Other current liabilities	21	(54)
Total current liabilities	817	271
Long-term debt	0	0
Intercompany loans payable	0	0
Pension and other postretirement benefits	0	0
Other non-current liabilities	74	74
Total liabilities	891	345
Redeemable noncontrolling interest	0	0
Equity:
Common stock	0	0
Additional paid-in capital	602	1,154
Retained income	516	176
Accumulated other comprehensive loss	0	0
Less: common stock in treasury	0	0
Total equity – controlling interests	1,118	1,330
Total equity – noncontrolling interests	0	0
Total equity	1,118	1,330
Total liabilities and equity	2,009	1,675
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current assets:
Cash and cash equivalents	2,147	1,681	$ 1,314	$ 1,095
Accounts receivable, net of allowance for doubtful accounts	1,029	853
Intercompany receivable	2,527	870
Prepaid and other current assets	86	79
Total current assets	5,789	3,483
Property and equipment, net of accumulated depreciation	107	111
Goodwill	2,719	2,679
Other intangible assets, net	1,388	1,506
Investments in subsidiaries	8,028	7,826
Intercompany loans receivable	1,699	1,354
Other non-current assets	174	114
Total assets	19,904	17,073
Current liabilities:
Accounts payable	93	88
Intercompany payable	1,154	177
Accrued compensation and contributions to retirement plans	241	211
Short-term debt	0
Income taxes currently payable	75	52
Unearned revenue	1,127	1,045
Accrued legal and regulatory settlements	105	51
Other current liabilities	194	250
Total current liabilities	2,989	1,874
Long-term debt	0	0
Intercompany loans payable	1,715	1,360
Pension and other postretirement benefits	64	78
Other non-current liabilities	229	314
Total liabilities	4,997	3,626
Redeemable noncontrolling interest	0	0
Equity:
Common stock	2,318	2,460
Additional paid-in capital	9,256	10,485
Retained income	3,782	1,034
Accumulated other comprehensive loss	(426)	(525)
Less: common stock in treasury	(23)	(7)
Total equity – controlling interests	14,907	13,447
Total equity – noncontrolling interests	0	0
Total equity	14,907	13,447
Total liabilities and equity	$ 19,904	$ 17,073