Condensed Consolidating Financial Statements (Statement of Cash Flows) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income	$ 430	$ 323
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	19	18
Amortization of intangibles	24	24
Provision for losses on accounts receivable	5	3
Deferred income taxes	(1)	(1)
Stock-based compensation	19	14
Other	14	31
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable	12	(7)
Prepaid and other current assets	9	(12)
Accounts payable and accrued expenses	(235)	(237)
Unearned revenue	(6)	39
Accrued legal settlements	(1)	(108)
Other current liabilities	(58)	24
Net change in prepaid/accrued income taxes	146	105
Net change in other assets and liabilities	(24)	(31)
Cash provided by operating activities	353	185
Investing Activities:
Capital expenditures	(23)	(16)
Acquisitions, net of cash acquired	(1)	(7)
Proceeds from dispositions	2	0
Changes in short-term investments	0	(1)
Cash used for investing activities	(22)	(24)
Financing Activities:
Additions to short-term debt, net	0	329
Dividends paid to shareholders	(106)	(96)
Dividends and other payments paid to noncontrolling interests	(24)	(33)
Repurchase of treasury shares	(201)	(226)
Exercise of stock options	29	31
Employee withholding tax on share-based payments	(44)	(46)
Intercompany financing activities	0	0
Cash used for financing activities	(346)	(41)
Effect of exchange rate changes on cash from continuing operations	34	(1)
Net change in cash and cash equivalents	19	119
Cash and cash equivalents at beginning of period	2,392	1,481
Cash and cash equivalents at end of period	2,411	1,600
Eliminations
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income	(2,062)	(1,290)
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	0	0
Amortization of intangibles	0	0
Provision for losses on accounts receivable	0	0
Deferred income taxes	0	0
Stock-based compensation	0	0
Other	0	0
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable	0	0
Prepaid and other current assets	0	0
Accounts payable and accrued expenses	0	0
Unearned revenue	0	0
Accrued legal settlements	0	0
Other current liabilities	0	0
Net change in prepaid/accrued income taxes	0	0
Net change in other assets and liabilities	0	0
Cash provided by operating activities	(2,062)	(1,290)
Investing Activities:
Capital expenditures	0	0
Acquisitions, net of cash acquired	0	0
Proceeds from dispositions	0
Changes in short-term investments		0
Cash used for investing activities	0	0
Financing Activities:
Additions to short-term debt, net		0
Dividends paid to shareholders	0	0
Dividends and other payments paid to noncontrolling interests	0	0
Repurchase of treasury shares	0	0
Exercise of stock options	0	0
Employee withholding tax on share-based payments	0	0
Intercompany financing activities	2,062	1,290
Cash used for financing activities	2,062	1,290
Effect of exchange rate changes on cash from continuing operations	0	0
Net change in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
S&P Global Inc.
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income	1,236	794
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	7	9
Amortization of intangibles	0	0
Provision for losses on accounts receivable	1	0
Deferred income taxes	(1)	(1)
Stock-based compensation	7	4
Other	6	3
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable	8	(7)
Prepaid and other current assets	8	5
Accounts payable and accrued expenses	(61)	(52)
Unearned revenue	5	15
Accrued legal settlements	0	0
Other current liabilities	(35)	(10)
Net change in prepaid/accrued income taxes	123	104
Net change in other assets and liabilities	(6)	(17)
Cash provided by operating activities	1,298	847
Investing Activities:
Capital expenditures	(4)	(4)
Acquisitions, net of cash acquired	0	0
Proceeds from dispositions	0
Changes in short-term investments		0
Cash used for investing activities	(4)	(4)
Financing Activities:
Additions to short-term debt, net		329
Dividends paid to shareholders	(106)	(96)
Dividends and other payments paid to noncontrolling interests	0	0
Repurchase of treasury shares	(201)	(226)
Exercise of stock options	29	31
Employee withholding tax on share-based payments	(44)	(46)
Intercompany financing activities	(1,056)	(838)
Cash used for financing activities	(1,378)	(846)
Effect of exchange rate changes on cash from continuing operations	0	7
Net change in cash and cash equivalents	(84)	4
Cash and cash equivalents at beginning of period	711	167
Cash and cash equivalents at end of period	627	171
Standard & Poor's Financial Services LLC
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income	148	185
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	3	2
Amortization of intangibles	0	0
Provision for losses on accounts receivable	1	1
Deferred income taxes	0	0
Stock-based compensation	4	3
Other	0	3
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable	(59)	153
Prepaid and other current assets	3	(3)
Accounts payable and accrued expenses	12	(89)
Unearned revenue	25	(374)
Accrued legal settlements	(1)	(108)
Other current liabilities	(3)	(19)
Net change in prepaid/accrued income taxes	0	0
Net change in other assets and liabilities	(4)	30
Cash provided by operating activities	129	(216)
Investing Activities:
Capital expenditures	(4)	(4)
Acquisitions, net of cash acquired	0	0
Proceeds from dispositions	0
Changes in short-term investments		0
Cash used for investing activities	(4)	(4)
Financing Activities:
Additions to short-term debt, net		0
Dividends paid to shareholders	0	0
Dividends and other payments paid to noncontrolling interests	0	0
Repurchase of treasury shares	0	0
Exercise of stock options	0	0
Employee withholding tax on share-based payments	0	0
Intercompany financing activities	(125)	220
Cash used for financing activities	(125)	220
Effect of exchange rate changes on cash from continuing operations	0	0
Net change in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Non-Guarantor Subsidiaries
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net income	1,108	634
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	9	7
Amortization of intangibles	24	24
Provision for losses on accounts receivable	3	2
Deferred income taxes	0	0
Stock-based compensation	8	7
Other	8	25
Changes in operating assets and liabilities, net of effect of acquisitions and dispositions:
Accounts receivable	63	(153)
Prepaid and other current assets	(2)	(14)
Accounts payable and accrued expenses	(186)	(96)
Unearned revenue	(36)	398
Accrued legal settlements	0	0
Other current liabilities	(20)	53
Net change in prepaid/accrued income taxes	23	1
Net change in other assets and liabilities	(14)	(44)
Cash provided by operating activities	988	844
Investing Activities:
Capital expenditures	(15)	(8)
Acquisitions, net of cash acquired	(1)	(7)
Proceeds from dispositions	2
Changes in short-term investments		(1)
Cash used for investing activities	(14)	(16)
Financing Activities:
Additions to short-term debt, net		0
Dividends paid to shareholders	0	0
Dividends and other payments paid to noncontrolling interests	(24)	(33)
Repurchase of treasury shares	0	0
Exercise of stock options		0
Employee withholding tax on share-based payments		0
Intercompany financing activities	(881)	(672)
Cash used for financing activities	(905)	(705)
Effect of exchange rate changes on cash from continuing operations	34	(8)
Net change in cash and cash equivalents	103	115
Cash and cash equivalents at beginning of period	1,681	1,314
Cash and cash equivalents at end of period	$ 1,784	$ 1,429