Other, Net (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	$ 56	$ (7)	$ 45
Interest and dividend income [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	12	14	24
Loss on redemption of MEHC subordinated debt [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	0	(40)	0
Corporate-owned life insurance income [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	21	9	17
Other, net [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Other, net	$ 23	$ 10	$ 4