Restructuring (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			3 Months Ended					12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended		3 Months Ended		12 Months Ended
	Mar. 31, 2013 Restructuring Plan, 2012 [Member] Positions	Dec. 31, 2012 Restructuring Plan, 2012 [Member]	Dec. 31, 2011 Restructuring Plan, 2012 [Member]	Mar. 31, 2013 Restructuring Plan, 2011 [Member]	Mar. 31, 2012 Restructuring Plan, 2011 [Member]	Dec. 31, 2011 Restructuring Plan, 2011 [Member] Positions	Mar. 31, 2013 Growth And Value Plan [Member]	Mar. 31, 2013 MHE [Member] Restructuring Plan, 2012 [Member]	Dec. 31, 2011 MHE [Member] Restructuring Plan, 2012 [Member]	Mar. 31, 2013 S&P Ratings [Member] Restructuring Plan, 2012 [Member]	Dec. 31, 2011 S&P Ratings [Member] Restructuring Plan, 2012 [Member]	Mar. 31, 2013 S&P Capital IQ / Indices [Member] Restructuring Plan, 2012 [Member]	Mar. 31, 2013 S&P/DJ Indices [Member] Restructuring Plan, 2012 [Member]	Mar. 31, 2013 C&C [Member] Restructuring Plan, 2012 [Member]	Mar. 31, 2013 Corporate Segment [Member] Restructuring Plan, 2012 [Member]	Dec. 31, 2011 Corporate Segment [Member] Restructuring Plan, 2012 [Member]
Restructuring (Textual) [Abstract]
Pre-tax restructuring charge	$ 68					$ 32	$ 5	$ 12	$ 6	$ 15	$ 9	$ 19		$ 1	$ 21	$ 17
Restructuring reserve		107	66
Workforce reduction, positions	670					250
Restructuring charges paid	24			5	18
Restructuring reserve, current	$ 68			$ 15				$ 23		$ 13		$ 11	$ 1	$ 6	$ 14