Segment Information 1 (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2015		Dec. 31, 2014
Segment information
Revenue	$ 1,034		$ 1,091		$ 3,016		$ 3,239
Income from continuing operations before interest and income taxes	293		318		856		951
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	293		318		856		951
Share-based compensation expense	25		23		70		65
Other (gains) expenses, net	(4)	[1]	(6)	[2]	(2)	[1]	2	[3]
Interest expense, net	15		12		36		38
Income from continuing operations before income taxes	278		306		820		913
Purchased Software Products
Reconciliation of segment profit to income from continuing operations before income taxes
Amortization of intangible assets	39		28		106		87
Other Intangible Assets
Reconciliation of segment profit to income from continuing operations before income taxes
Amortization of intangible assets	11		14		36		45
Internally Developed Software Products
Reconciliation of segment profit to income from continuing operations before income taxes
Amortization of intangible assets	26		34		86		117
Mainframe Solutions
Segment information
Revenue	554		596		1,668		1,820
Expenses	218		248		641		717
Income from continuing operations before interest and income taxes	$ 336		$ 348		$ 1,027		$ 1,103
Segment operating margin	61.00%		58.00%		62.00%		61.00%
Depreciation	$ 9		$ 10		$ 27		$ 33
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	336		348		1,027		1,103
Enterprise Solutions
Segment information
Revenue	398		405		1,104		1,151
Expenses	349		347		996		999
Income from continuing operations before interest and income taxes	$ 49		$ 58		$ 108		$ 152
Segment operating margin	12.00%		14.00%		10.00%		13.00%
Depreciation	$ 7		$ 7		$ 20		$ 21
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	49		58		108		152
Services
Segment information
Revenue	82		90		244		268
Expenses	77		85		227		256
Income from continuing operations before interest and income taxes	$ 5		$ 5		$ 17		$ 12
Segment operating margin	6.00%		6.00%		7.00%		4.00%
Depreciation	$ 0		$ 0		$ 0		$ 0
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	5		5		17		12
Total Reportable Segments
Segment information
Revenue	1,034		1,091		3,016		3,239
Expenses	644		680		1,864		1,972
Income from continuing operations before interest and income taxes	$ 390		$ 411		$ 1,152		$ 1,267
Segment operating margin	38.00%		38.00%		38.00%		39.00%
Depreciation	$ 16		$ 17		$ 47		$ 54
Reconciliation of segment profit to income from continuing operations before income taxes
Segment profit	$ 390		$ 411		$ 1,152		$ 1,267

[1] Other gains, net consists of costs associated with certain foreign exchange derivative hedging gains and losses, and other miscellaneous costs.

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