Severance and Leased Real Estate (Schedule Of Restructuring Reserve By Type Of Cost) (Details) (USD $) In Millions	6 Months Ended	3 Months Ended
Sep. 30, 2011 Successor [Member] Real Estate Restructuring [Member]	Sep. 30, 2011 Successor [Member] Severance [Member]	Mar. 31, 2011 Predecessor [Member] Real Estate Restructuring [Member]	Mar. 31, 2011 Predecessor [Member] Severance [Member]	Mar. 31, 2011 Real Estate Restructuring [Member]
Beginning Balance	$ 168	$ 20	$ 223	$ 29
Accrued to expense	12	101	4	3
Payments, net	(14)	(83)	(12)	(12)
Ending Balance	166	38	215	20
Fair value adjustment					$ (47)

Amount of cash paid in the period to fully or partially settle a specified, previously accrued type of restructuring cost.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b)(2))

-URI http://asc.fasb.org/extlink&oid=6394695&loc=d3e140904-122747

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b) (2)

-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

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

-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 95-3

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 146

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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