Goodwill and Intangible Assets, Net (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Mar. 31, 2011
Intangible assets
Gross carrying amount	$ 2,142		$ 2,136
Accumulated amortization	(728)		(680)
Net carrying amount	1,414		1,456
Goodwill and Intangible Assets, Net (Textuals)
Amortization expense of intangible assets	48	28
Annual amortization expense, 2012	190
Annual amortization expense, 2013	172
Annual amortization expense, 2014	158
Annual amortization expense, 2015	140
Annual amortization expense, 2016	119
Annual amortization expense, after 2016	683
Customer Lists [Member]
Intangible assets
Weighted average remaining amortization period (years)	7
Gross carrying amount	1,076		1,057
Accumulated amortization	(472)		(444)
Net carrying amount	604		613
Service agreements [Member]
Intangible assets
Weighted average remaining amortization period (years)	17
Gross carrying amount	688		723
Accumulated amortization	(22)		(11)
Net carrying amount	666		712
Trade Names [Member]
Intangible assets
Weighted average remaining amortization period (years)	14
Gross carrying amount	79		76
Accumulated amortization	(33)		(31)
Net carrying amount	46		45
Technology [Member]
Intangible assets
Weighted average remaining amortization period (years)	4
Gross carrying amount	223		204
Accumulated amortization	(175)		(170)
Net carrying amount	48		34
Other Intangible Assets [Member]
Intangible assets
Weighted average remaining amortization period (years)	9
Gross carrying amount	76		76
Accumulated amortization	(26)		(24)
Net carrying amount	$ 50		$ 52