Acquisitions and Divestitures (Divestitures) (Narrative) (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended		6 Months Ended
	Nov. 03, 2014	Jul. 31, 2014	Jun. 30, 2015	Dec. 31, 2013	Jun. 30, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from sale of business			$ 11		$ 11
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 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from sale of business	$ 320