Financial Instruments (Securities Repurchase and Reverse Repurchase Arrangements) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015
short-term borrowings
Financial Instruments [Line Items]
Securities for Reverse Repurchase Agreements	$ 45
Cash and cash equivalents
Financial Instruments [Line Items]
Securities for Reverse Repurchase Agreements	$ 12,100

The carrying value of securities purchased to be resold in reverse repurchase transactions as of the balance sheet date.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(m)(2)(i))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Name:	us-gaap_SecuritiesForReverseRepurchaseAgreements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant