Condensed Consolidating Financial Statements - Statement of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Activities:
Net income (loss)	$ 569	$ 923	$ 412	$ 323	$ 276	$ 281	$ 381	$ 329	$ 2,228	$ 1,268	$ (13)
Less: income from discontinued operations									0	0	178
Net income (loss) from continuing operations									2,228	1,268	(191)
Adjustments to reconcile income from continuing operations to cash provided by (used for) operating activities from continuing operations:
Depreciation									85	90	86
Amortization of intangibles									96	67	48
Provision for losses on accounts receivable									9	8	11
Deferred income taxes									79	280	(245)
Stock-based compensation									76	78	100
Gain on dispositions									(1,101)	(11)	9
Accrued legal and regulatory settlements									54	119	1,587
Other									30	57	71
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable									(177)	(118)	(9)
Prepaid and other current assets									(2)	(4)	(7)
Accounts payable and accrued expenses									(26)	(92)	(130)
Unearned revenue									107	129	78
Accrued legal and regulatory settlements									(150)	(1,624)	(35)
Other current liabilities									(21)	(78)	(16)
Net change in prepaid / accrued income taxes									132	61	(93)
Net change in other assets and liabilities									45	(35)	(55)
Cash provided by operating activities from continuing operations									1,464	195	1,209
Investing Activities:
Capital expenditures									(115)	(139)	(92)
Acquisitions, net of cash acquired									(177)	(2,396)	(71)
Proceeds from dispositions									1,498	14	83
Changes in short-term investments									(1)	(4)	15
Cash provided by (used for) investing activities from continuing operations									1,205	(2,525)	(65)
Financing Activities:
(Payments on) / additions to short-term debt, net									(143)	143	0
Proceeds from issuance of senior notes, net									493	2,674	0
Payments on senior notes									(421)	0	0
Dividends paid to shareholders									(380)	(363)	(326)
Dividends and other payments paid to noncontrolling interests									(116)	(104)	(84)
Repurchase of treasury shares									(1,123)	(974)	(362)
Exercise of stock options									88	86	193
Contingent consideration payments									(39)	(5)	(11)
Purchase of additional CRISIL shares									0	(16)	0
Excess tax benefits from share-based payments									41	69	128
Intercompany financing activities									0	0	0
Cash (used for) provided by financing activities from continuing operations									(1,600)	1,510	(462)
Effect of exchange rate changes on cash from continuing operations									(158)	(67)	(65)
Cash provided by (used for) continuing operations									911	(887)	617
Discontinued Operations:
Cash (used for) provided by operating activities									0	(129)	18
Cash provided by investing activities									0	0	320
Cash (used for) provided by discontinued operations									0	(129)	338
Net change in cash and cash equivalents									911	(1,016)	955
Cash and cash equivalents at beginning of year				1,481				2,497	1,481	2,497	1,542
Cash and cash equivalents at end of year	2,392				1,481				2,392	1,481	2,497
Eliminations
Operating Activities:
Net income (loss)									(3,374)	(1,745)	195
Less: income from discontinued operations											0
Net income (loss) from continuing operations											195
Adjustments to reconcile income from continuing operations to cash provided by (used for) operating activities from continuing operations:
Depreciation									0	0	0
Amortization of intangibles									0	0	0
Provision for losses on accounts receivable									0	0	0
Deferred income taxes									0	0	0
Stock-based compensation									0	0	0
Gain on dispositions									0	0	0
Accrued legal and regulatory settlements									0	0	0
Other									0	0	0
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable									0	0	0
Prepaid and other current assets									0	0	0
Accounts payable and accrued expenses									0	0	0
Unearned revenue									0	0	0
Accrued legal and regulatory settlements									0	0	0
Other current liabilities									0	0	0
Net change in prepaid / accrued income taxes									0	0	0
Net change in other assets and liabilities									0	0	0
Cash provided by operating activities from continuing operations									(3,374)	(1,745)	195
Investing Activities:
Capital expenditures									0	0	0
Acquisitions, net of cash acquired									0	0	0
Proceeds from dispositions									0	0	0
Changes in short-term investments									0	0	0
Cash provided by (used for) investing activities from continuing operations									0	0	0
Financing Activities:
(Payments on) / additions to short-term debt, net									0	0
Proceeds from issuance of senior notes, net									0	0
Payments on senior notes									0
Dividends paid to shareholders									0	0	0
Dividends and other payments paid to noncontrolling interests									0	0	0
Repurchase of treasury shares									0	0	0
Exercise of stock options									0	0	0
Contingent consideration payments									0	0	0
Purchase of additional CRISIL shares										0
Excess tax benefits from share-based payments									0	0	0
Intercompany financing activities									3,374	1,745	(195)
Cash (used for) provided by financing activities from continuing operations									3,374	1,745	(195)
Effect of exchange rate changes on cash from continuing operations									0	0	0
Cash provided by (used for) continuing operations										0	0
Discontinued Operations:
Cash (used for) provided by operating activities										0	0
Cash provided by investing activities											0
Cash (used for) provided by discontinued operations										0	0
Net change in cash and cash equivalents									0	0	0
Cash and cash equivalents at beginning of year				0				0	0	0	0
Cash and cash equivalents at end of year	0				0				0	0	0
S&P Global Inc. | Reportable Legal Entities
Operating Activities:
Net income (loss)									3,069	1,449	(326)
Less: income from discontinued operations											178
Net income (loss) from continuing operations											(504)
Adjustments to reconcile income from continuing operations to cash provided by (used for) operating activities from continuing operations:
Depreciation									38	40	41
Amortization of intangibles									0	0	4
Provision for losses on accounts receivable									1	1	0
Deferred income taxes									16	33	42
Stock-based compensation									22	23	31
Gain on dispositions									(1,072)	0	3
Accrued legal and regulatory settlements									3	0	0
Other									48	23	18
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable									(24)	3	(11)
Prepaid and other current assets									(9)	(13)	(42)
Accounts payable and accrued expenses									(53)	(75)	(83)
Unearned revenue									19	(5)	8
Accrued legal and regulatory settlements									0	0	0
Other current liabilities									(29)	(32)	(51)
Net change in prepaid / accrued income taxes									99	(54)	13
Net change in other assets and liabilities									(9)	78	(131)
Cash provided by operating activities from continuing operations									2,119	1,471	(662)
Investing Activities:
Capital expenditures									(68)	(67)	(26)
Acquisitions, net of cash acquired									(144)	(2,243)	0
Proceeds from dispositions									1,422	0	63
Changes in short-term investments									0	0	0
Cash provided by (used for) investing activities from continuing operations									1,210	(2,310)	37
Financing Activities:
(Payments on) / additions to short-term debt, net									(143)	143
Proceeds from issuance of senior notes, net									493	2,674
Payments on senior notes									(421)
Dividends paid to shareholders									(380)	(363)	(326)
Dividends and other payments paid to noncontrolling interests									0	0	0
Repurchase of treasury shares									(1,123)	(974)	(362)
Exercise of stock options									86	80	184
Contingent consideration payments									(5)	(5)	0
Purchase of additional CRISIL shares										0
Excess tax benefits from share-based payments									41	69	128
Intercompany financing activities									(1,333)	(2,020)	1,377
Cash (used for) provided by financing activities from continuing operations									(2,785)	(396)	1,001
Effect of exchange rate changes on cash from continuing operations									0	0	3
Cash provided by (used for) continuing operations										(1,235)	379
Discontinued Operations:
Cash (used for) provided by operating activities										0	18
Cash provided by investing activities											320
Cash (used for) provided by discontinued operations										0	338
Net change in cash and cash equivalents									544	(1,235)	717
Cash and cash equivalents at beginning of year				167				1,402	167	1,402	685
Cash and cash equivalents at end of year	711				167				711	167	1,402
Standard & Poor's Financial Services LLC | Reportable Legal Entities
Operating Activities:
Net income (loss)									767	824	(519)
Less: income from discontinued operations											0
Net income (loss) from continuing operations											(519)
Adjustments to reconcile income from continuing operations to cash provided by (used for) operating activities from continuing operations:
Depreciation									9	18	17
Amortization of intangibles									0	0	0
Provision for losses on accounts receivable									0	1	5
Deferred income taxes									(9)	290	(272)
Stock-based compensation									17	24	34
Gain on dispositions									0	0	0
Accrued legal and regulatory settlements									1	110	1,587
Other									5	16	39
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable									187	(27)	47
Prepaid and other current assets									10	14	(17)
Accounts payable and accrued expenses									(39)	(34)	(47)
Unearned revenue									(395)	66	26
Accrued legal and regulatory settlements									(108)	(1,624)	(35)
Other current liabilities									(27)	(35)	45
Net change in prepaid / accrued income taxes									0	0	3
Net change in other assets and liabilities									38	8	5
Cash provided by operating activities from continuing operations									456	(349)	918
Investing Activities:
Capital expenditures									(15)	(10)	(14)
Acquisitions, net of cash acquired									0	0	0
Proceeds from dispositions									0	0	0
Changes in short-term investments									0	0	0
Cash provided by (used for) investing activities from continuing operations									(15)	(10)	(14)
Financing Activities:
(Payments on) / additions to short-term debt, net									0	0
Proceeds from issuance of senior notes, net									0	0
Payments on senior notes									0
Dividends paid to shareholders									0	0	0
Dividends and other payments paid to noncontrolling interests									0	0	0
Repurchase of treasury shares									0	0	0
Exercise of stock options									0	0	0
Contingent consideration payments									0	0	0
Purchase of additional CRISIL shares										0
Excess tax benefits from share-based payments									0	0	0
Intercompany financing activities									(441)	359	(904)
Cash (used for) provided by financing activities from continuing operations									(441)	359	(904)
Effect of exchange rate changes on cash from continuing operations									0	0	0
Cash provided by (used for) continuing operations										0	0
Discontinued Operations:
Cash (used for) provided by operating activities										0	0
Cash provided by investing activities											0
Cash (used for) provided by discontinued operations										0	0
Net change in cash and cash equivalents									0	0	0
Cash and cash equivalents at beginning of year				0				0	0	0	0
Cash and cash equivalents at end of year	0				0				0	0	0
Non-Guarantor Subsidiaries | Reportable Legal Entities
Operating Activities:
Net income (loss)									1,766	740	637
Less: income from discontinued operations											0
Net income (loss) from continuing operations											637
Adjustments to reconcile income from continuing operations to cash provided by (used for) operating activities from continuing operations:
Depreciation									38	32	28
Amortization of intangibles									96	67	44
Provision for losses on accounts receivable									8	6	6
Deferred income taxes									72	(43)	(15)
Stock-based compensation									37	31	35
Gain on dispositions									(29)	(11)	6
Accrued legal and regulatory settlements									50	9	0
Other									(23)	18	14
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable									(340)	(94)	(45)
Prepaid and other current assets									(3)	(5)	52
Accounts payable and accrued expenses									66	17	0
Unearned revenue									483	68	44
Accrued legal and regulatory settlements									(42)	0	0
Other current liabilities									35	(11)	(10)
Net change in prepaid / accrued income taxes									33	115	(109)
Net change in other assets and liabilities									16	(121)	71
Cash provided by operating activities from continuing operations									2,263	818	758
Investing Activities:
Capital expenditures									(32)	(62)	(52)
Acquisitions, net of cash acquired									(33)	(153)	(71)
Proceeds from dispositions									76	14	20
Changes in short-term investments									(1)	(4)	15
Cash provided by (used for) investing activities from continuing operations									10	(205)	(88)
Financing Activities:
(Payments on) / additions to short-term debt, net									0	0
Proceeds from issuance of senior notes, net									0	0
Payments on senior notes									0
Dividends paid to shareholders									0	0	0
Dividends and other payments paid to noncontrolling interests									(116)	(104)	(84)
Repurchase of treasury shares									0	0	0
Exercise of stock options									2	6	9
Contingent consideration payments									(34)	0	(11)
Purchase of additional CRISIL shares										(16)
Excess tax benefits from share-based payments									0	0	0
Intercompany financing activities									(1,600)	(84)	(278)
Cash (used for) provided by financing activities from continuing operations									(1,748)	(198)	(364)
Effect of exchange rate changes on cash from continuing operations									(158)	(67)	(68)
Cash provided by (used for) continuing operations										348	238
Discontinued Operations:
Cash (used for) provided by operating activities										(129)	0
Cash provided by investing activities											0
Cash (used for) provided by discontinued operations										(129)	0
Net change in cash and cash equivalents									367	219	238
Cash and cash equivalents at beginning of year				$ 1,314				$ 1,095	1,314	1,095	857
Cash and cash equivalents at end of year	$ 1,681				$ 1,314				$ 1,681	$ 1,314	$ 1,095