Acquisitions and Divestitures - Divestitures Narrative (Details) $ in Millions				1 Months Ended			3 Months Ended				12 Months Ended
	Nov. 03, 2014 USD ($)	Jul. 31, 2014 USD ($)	Jun. 30, 2014 USD ($)	Nov. 30, 2016 USD ($)	Oct. 31, 2016 USD ($) business	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions							$ 379	$ 722			$ 1,100
Gain on dispositions											1,101	$ 11	$ (9)
Gain (loss) on disposition of business, net of tax							$ 297	$ 521
Non-cash impairment charge on long-lived assets to be disposed										$ 36
Gain on sale of discontinued operations											$ 0	0	160
Data Center
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from sale of business			$ 58
Disposal Group, Held-for-sale, Not Discontinued Operations | QuantHouse
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on write-down				$ 31
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions													(9)
Non-cash impairment charge on long-lived assets to be disposed									$ 6
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Equity Research
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions					$ 9
Gain (loss) on disposition of business, net of tax					5
Disposal Group, Disposed of by Sale, Not Discontinued Operations | SPSE and CMA
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions					364
Gain (loss) on disposition of business, net of tax					$ 297
Number of businesses disposed | business					2
Cash proceeds from sale of business					$ 425
Disposal Group, Disposed of by Sale, Not Discontinued Operations | J.D. Power
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions						$ 728
Gain (loss) on disposition of business, net of tax						516
Cash proceeds from sale of business						$ 1,100
Disposal Group, Disposed of by Sale, Not Discontinued Operations | McGraw Hill Construction
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions												$ 11
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Data Center
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on dispositions			(3)
Cash proceeds from sale of business			$ 58
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Harold W. McGraw III
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Amount of transaction with related party		$ 20
Discontinued Operations, Disposed of by Sale | McGraw Hill Construction
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from sale of business	$ 320
Gain on sale of discontinued operations													$ 160