Acquisitions and Divestitures (Divestitures) (Narrative) (Details) - USD ($) $ in Millions			1 Months Ended	3 Months Ended			9 Months Ended
	Nov. 03, 2014	Jul. 31, 2014	Jul. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013	Sep. 30, 2015
Other (Income) Loss [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Non-cash impairment charge				$ 6	$ 6
Harold W. McGraw III [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Transaction amount		$ 20
e-Builder [Member] | Other (Income) Loss [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from sale of business							$ 11
Data Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from sale of business			$ 58
Data Center [Member] | Other (Income) Loss [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
After-tax gain (loss) on sale of business						$ 3
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