Acquisitions and Divestitures (Acquisitions) (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	6 Months Ended		9 Months Ended		1 Months Ended
	Mar. 31, 2014 Country company	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Aug. 31, 2014 CRISIL Limited [Member]	Jun. 30, 2014 CRISIL Limited [Member]
Subsidiary or Equity Method Investee [Line Items]
Minimum Number of Companies Represented in Broad Market Indices	11,000
Minimum Number of Countries Represented in Broad Market Indices	52
Sale of Stock, Percentage of Total Outstanding Equity Shares Offered for Purchase							22.23%
Sale of Stock, Number of Shares Issued in Transaction						11
Sale of Stock, Percentage of Total Outstanding Equity Shares						15.07%
Sale of Stock, Consideration Received on Transaction						$ 214
Sale of Stock, Percentage of Ownership after Transaction						67.84%
Sale of Stock, Percentage of Ownership before Transaction						52.77%
Contingent consideration payment		$ 11	$ 12	$ 11	$ 12