Employee Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Sep. 30, 2011
Retirement Plans [Member]
Components of net periodic cost for retirement plans and post-retirement plans
Service cost	$ 4		$ 19
Interest cost	22		23
Expected return on plan assets	(32)		(31)
Amortization of actuarial loss	6		8
Curtailment gain	(2)		0
Net periodic benefit cost	(2)	[1]	19	[1]
Post-Retirement Plans [Member]
Components of net periodic cost for retirement plans and post-retirement plans
Service cost	1		1
Interest cost	1		1
Curtailment gain	(9)		0
Net periodic benefit cost	$ (7)	[2]	$ 2	[2]

[1] The decrease reflects the reduction in service cost resulting from a freeze of our U.S. ERP in 2012 as discussed above as well as a curtailment gain due to a freeze of pension accruals for MHE employees in the United Kingdom ("U.K.") retirement plan during 2012.

[2] The decrease reflects a curtailment gain related to the sale of MHE on March 22, 2013, which was recorded within discontinued operations in our consolidated statement of income.