Acquisitions and Divestitures (Components of Assets and Liabilities, and Operating Profits, of Businesses Held for Sale) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Assets and Liabilities of Business Held for Sale
Liabilities of businesses held for sale	$ 207		$ 207		$ 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	72		72		58
Goodwill	133		133		75
Other intangible assets, net	309		309		335
Other assets	60		60		35
Assets of businesses held for sale	574		574		503
Accounts payable and accrued expenses	35		35		42
Unearned revenue	66		66		64
Other liabilities	106		106		100
Liabilities of businesses held for sale	207		207		$ 206
Operating Profit of Business Held for Sale
Operating profit	$ 20	$ 22	$ 44	$ 38