Restructuring And Other Charges (Narrative) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended		3 Months Ended	12 Months Ended			6 Months Ended	12 Months Ended	6 Months Ended	15 Months Ended	6 Months Ended	12 Months Ended			6 Months Ended		12 Months Ended			3 Months Ended	12 Months Ended	18 Months Ended	6 Months Ended	12 Months Ended	18 Months Ended			6 Months Ended	12 Months Ended	18 Months Ended			6 Months Ended	12 Months Ended	18 Months Ended					12 Months Ended		6 Months Ended	12 Months Ended		12 Months Ended			6 Months Ended
	Sep. 30, 2011	Mar. 31, 2011	Mar. 31, 2010	Sep. 30, 2011 Maximum [Member] Fiscal 2010 Restructuring [Member] Expected By March 31, 2012 [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member]	Mar. 31, 2011 Fiscal 2011 Restructuring [Member] Developer Commitments [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member] Amended Licensing Agreements [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member] Amended Licensing Agreements [Member] Accretion of Interest [Member] June 2016 [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member] Amended Licensing Agreements and Other Asset Impairment [Member] Asset Impairment [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member] Amended Licensing and Developer Agreements [Member] Expected by June 2016 [Member]	Jun. 30, 2011 Fiscal 2011 Restructuring [Member] Amended Developer Agreements [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member] Workforce [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member] Workforce [Member]	Mar. 31, 2011 Fiscal 2011 Restructuring [Member] Workforce [Member]	Mar. 31, 2010 Fiscal 2011 Restructuring [Member] Workforce [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member] Workforce [Member] Expected by June 2016 [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member] Other Reorganizational Cost [Member]	Mar. 31, 2011 Fiscal 2011 Restructuring [Member] Other Reorganizational Cost [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member] June 2016 [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member] Expected by June 2016 [Member]	Sep. 30, 2011 Fiscal 2011 Restructuring [Member] Expected By March 31, 2012 [Member]	Mar. 31, 2010 Fiscal 2010 Restructuring [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member] Facilities-Related [Member]	Mar. 31, 2011 Fiscal 2010 Restructuring [Member] Facilities-Related [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member] Facilities-Related [Member]	Mar. 31, 2010 Fiscal 2010 Restructuring [Member] Facilities-Related [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member] Facilities-Related [Member] Expected By March 31, 2012 [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member] Workforce [Member]	Mar. 31, 2011 Fiscal 2010 Restructuring [Member] Workforce [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member] Workforce [Member]	Mar. 31, 2010 Fiscal 2010 Restructuring [Member] Workforce [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member] Workforce [Member] Expected By March 31, 2012 [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member] Other Reorganizational Cost [Member]	Mar. 31, 2011 Fiscal 2010 Restructuring [Member] Other Reorganizational Cost [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member] Other Reorganizational Cost [Member]	Mar. 31, 2010 Fiscal 2010 Restructuring [Member] Other Reorganizational Cost [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member] Other Reorganizational Cost [Member] Expected By March 31, 2012 [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member] Expected By March 31, 2012 [Member]	Sep. 30, 2011 Fiscal 2010 Restructuring [Member] Expected By September 2013 [Member]	Mar. 31, 2011 Fiscal 2009 Restructuring [Member]	Mar. 31, 2009 Fiscal 2009 Restructuring [Member]	Sep. 30, 2011 Fiscal 2009 Restructuring [Member] Facilities-Related [Member]	Mar. 31, 2011 Fiscal 2009 Restructuring [Member] Facilities-Related [Member]	Mar. 31, 2010 Fiscal 2009 Restructuring [Member] Facilities-Related [Member]	Mar. 31, 2011 Fiscal 2009 Restructuring [Member] Workforce [Member]	Mar. 31, 2011 Fiscal 2009 Restructuring [Member] Asset Impairment [Member]	Sep. 30, 2011 Fiscal 2009 Restructuring [Member] Expected By September 2016 [Member]	Sep. 30, 2011 Fiscal 2008 Reorganization [Member]	Sep. 30, 2011 Fiscal 2008 Reorganization [Member] Facilities-Related [Member]
Restructuring And Other Charges [Line Items]
Percentage of workforce reduction																																										11.00%
Number of employees terminated																						1,100																				1,100
Number of facilities closed																																										10
Expected restructuring charges, minimum																			$ 180
Expected restructuring charges, maximum																			185									23					62					60	145
Charges to operations (Life-to-Date)					164		119		121		31		12										140			23					62					55					55			20		33	2
Restructuring reserve and accrual	110	117	29											3			99	101		99				3	6	3	11					8		6	5	6	7			9			2	2	3			2
Cash paid for restructuring plans	24	70										2		8			19	32						4	6					8				9	15									1						(10)
Expected restructuring costs				5				16		170						12					5
Charges to operations	17	161				31						(1)		13			17	135						1										10	13														10	(10)
Sale of facility	$ 26																																																$ 26