Deferred Revenue (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Mar. 31, 2012
Current:
Total deferred revenue (billed or collected) - current	$ 2,101	$ 2,658
Noncurrent:
Total deferred revenue (billed or collected) - noncurrent	826	972
Total deferred revenue (billed or collected)	2,927	3,630
Subscription and Maintenance [Member]
Current:
Total deferred revenue (billed or collected) - current	1,943	2,479
Noncurrent:
Total deferred revenue (billed or collected) - noncurrent	787	935
Professional Services [Member]
Current:
Total deferred revenue (billed or collected) - current	140	162
Noncurrent:
Total deferred revenue (billed or collected) - noncurrent	37	35
Financing Obligations and Other [Member]
Current:
Total deferred revenue (billed or collected) - current	18	17
Noncurrent:
Total deferred revenue (billed or collected) - noncurrent	$ 2	$ 2