Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Amount attributable to The McGraw-Hill Companies, Inc. common shareholders:
Income from continuing operations	$ 216	$ 211	$ 339	$ 332
Loss from discontinued operations, net of tax	0	0	0	(1)
Net income attributable to The McGraw-Hill Companies, Inc.	$ 216	$ 211	$ 339	$ 331
Basic weighted-average number of common shares outstanding	279.7	303.6	278.9	304.4
Effect of stock options and other dilutive securities	5.6	5.6	5.6	5.0
Diluted weighted-average number of common shares outstanding	285.3	309.2	284.5	309.4
Basic EPS:
Income from continuing operations	$ 0.77	$ 0.70	$ 1.22	$ 1.09
Loss from discontinued operations, net of tax	$ 0.00	$ 0.00	$ 0.00	$ 0.00
Net income	$ 0.77	$ 0.70	$ 1.22	$ 1.09
Diluted EPS:
Income from continuing operations	$ 0.76	$ 0.68	$ 1.19	$ 1.07
Loss from discontinued operations, net of tax	$ 0.00	$ 0.00	$ 0.00	$ 0.00
Net income	$ 0.76	$ 0.68	$ 1.19	$ 1.07
Restricted Stock [Member]
Common Shares Outstanding (Textual) [Abstract]
Outstanding shares not included in the computation of diluted earnings per share for both restricted stock and stock options			1.4	1.6
Stock Options [Member]
Common Shares Outstanding (Textual) [Abstract]
Outstanding shares not included in the computation of diluted earnings per share for both restricted stock and stock options	3.8	10.0	4.0	10.8