The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a (1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Segments of Business (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			12 Months Ended
	Mar. 31, 2013 Antitrust Class Action Lawsuit [Member]	Dec. 31, 2012 Antitrust Class Action Lawsuit [Member]	Sep. 30, 2012 Antitrust Class Action Lawsuit [Member]	Mar. 31, 2013 Distribution Solutions [Member]	Mar. 31, 2012 Distribution Solutions [Member]	Mar. 31, 2011 Distribution Solutions [Member]	Mar. 31, 2013 Distribution Solutions [Member] Antitrust Class Action Lawsuit [Member]	Mar. 31, 2011 Distribution Solutions [Member] Antitrust Class Action Lawsuit [Member]	Mar. 31, 2013 Distribution Solutions [Member] Nadro [Member]
Segment Reporting Information [Line Items]
Interest in Investee									49.00%
Percentage of revenue derived from services for Distribution Solutions segment				less than 2%	less than 2%	less than 2%
Litigation Settlement, Gross	$ 17	$ 8	$ 19				$ 44	$ 51