Acquisitions and Divestitures (Components of Assets and Liabilities, and Operating Profits, of Businesses Held for Sale) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Assets and Liabilities of Business Held for Sale
Liabilities of a business held for sale	$ 203		$ 206
J.D. Power, SPSE, and CMA | Disposal Group, Held-for-sale, Not Discontinued Operations
Assets and Liabilities of Business Held for Sale
Accounts receivable, net	76		58
Goodwill	133		75
Other intangible assets, net	309		335
Other assets	53		35
Assets of a business held for sale	571		503
Accounts payable and accrued expenses	30		42
Unearned revenue	70		64
Other liabilities	103		100
Liabilities of a business held for sale	203		$ 206
Operating Profit of Business Held for Sale
Operating profit	$ 24	$ 16