Segment Information 1 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Segment information
Revenue	$ 1,079		$ 1,105		$ 2,148		$ 2,200
Income from continuing operations before interest and income taxes	320		345		633		564
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	320		345		633		564
Software development costs capitalized	0		(8)		0		(31)
Share-based compensation expense	22		20		42		40
Other expenses, net	(4)	[1]	7	[2]	8	[3]	122	[4]
Interest expense, net	12		13		26		24
Income from continuing operations before income taxes	308		332		607		540
Purchased Software Products [Member]
Reconciliation of segment profit to income from continuing operations before income taxes
Amortization of intangible assets	31		31		59		59
Other Intangible Assets [Member]
Reconciliation of segment profit to income from continuing operations before income taxes
Amortization of intangible assets	16		15		31		29
Internally Developed Software Products [Member]
Reconciliation of segment profit to income from continuing operations before income taxes
Amortization of intangible assets	44		38		83		76
Mainframe Solutions [Member]
Segment information
Revenue	610		624		1,224		1,243
Expenses	234		232		469		475
Income from continuing operations before interest and income taxes	376		392		755		768
Segment operating margin	62.00%		63.00%		62.00%		62.00%
Depreciation	11		13		23		27
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	376		392		755		768
Enterprise Solutions [Member]
Segment information
Revenue	378		384		746		762
Expenses	327		337		652		688
Income from continuing operations before interest and income taxes	51		47		94		74
Segment operating margin	13.00%		12.00%		13.00%		10.00%
Depreciation	7		9		14		17
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	51		47		94		74
Services [Member]
Segment information
Revenue	91		97		178		195
Expenses	89		88		171		178
Income from continuing operations before interest and income taxes	2		9		7		17
Segment operating margin	2.00%		9.00%		4.00%		9.00%
Depreciation	0		0		0		0
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	2		9		7		17
Total Reportable Segments [Member]
Segment information
Revenue	1,079		1,105		2,148		2,200
Expenses	650		657		1,292		1,341
Income from continuing operations before interest and income taxes	429		448		856		859
Segment operating margin	40.00%		41.00%		40.00%		39.00%
Depreciation	18		22		37		44
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	$ 429		$ 448		$ 856		$ 859

[1] Other expenses, net consists of approximately $12 million of costs associated with the Fiscal 2014 Plan, certain foreign exchange derivative hedging gains and losses, and other miscellaneous costs.

[2] Other expenses, net consists of approximately $2 million of costs associated with the Fiscal 2014 Plan, certain foreign exchange derivative hedging gains and losses, and other miscellaneous costs.

[3] Other expenses, net consists of approximately $21 million of costs associated with the Fiscal 2014 Plan, certain foreign exchange derivative hedging gains and losses, and other miscellaneous costs.

[4] Other expenses, net consists of approximately $119 million of costs associated with the Fiscal 2014 Plan, certain foreign exchange derivative hedging gains and losses, and other miscellaneous costs.