Income Taxes 4 (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Deferred tax assets:
Share-based compensation	$ 38	$ 48
Accrued expenses	42	30
Net operating losses	158	173
Total deferred tax assets	730	818
Valuation allowances	(75)	(68)
Total deferred tax assets, net of valuation allowance	655	750
Deferred tax liabilities:
Depreciation	21	31
Capitalized development costs	209	206
Total deferred tax liabilities	364	426
Net deferred tax asset	291	324
Modified Accrual Basis Accounting for Revenue [Member]
Deferred tax assets:
Deferred tax assets, Other	379	447
Intangible Assets Amortizable for Tax Purposes [Member]
Deferred tax assets:
Deferred tax assets, Other	7	11
Deductible State Tax and Interest Benefits [Member]
Deferred tax assets:
Deferred tax assets, Other	51	56
Other [Member]
Deferred tax assets:
Deferred tax assets, Other	55	53
Purchased Software [Member]
Deferred tax liabilities:
Purchased software and other intangible assets	93	133
Other Intangible Assets [Member]
Deferred tax liabilities:
Purchased software and other intangible assets	$ 41	$ 56