Legal Actions (Details) (Liability for Contingent Litigation Losses [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2012
Liability for Contingent Litigation Losses [Member]
Legal Actions (Textual) [Abstract]
Loss Contingency, Range of Possible Loss, Portion Not Accrued	$ 927

The difference between the maximum amount of estimated loss and the amount recorded as of the balance sheet date.

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

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 14

-Paragraph 3

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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_LossContingencyRangeOfPossibleLossPortionNotAccrued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant