Segment Reporting (Details) (USD $) In Millions	3 Months Ended	6 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Revenue:
License	$ 229.7	$ 208.1	$ 419.2	$ 379.3
Maintenance	270.5	252.5	535.1	506.3
Professional services	56.5	41.7	104.8	77.6
Total revenue	556.7	502.3	1,059.1	963.2
Direct and allocated indirect segment operating expenses	340.3	310.9	672.2	615.0
Segment operating income	216.4	191.4	386.9	348.2
Unallocated operating expenses	(55.4)	(47.9)	(110.8)	(96.6)
Other income (loss), net	(4.8)	0.3	(6.4)	(5.2)
Earnings before income taxes	156.2	143.8	269.7	246.4
Enterprise Service Management [Member]
Revenue:
License	146.0	131.3	264.5	244.5
Maintenance	145.6	136.4	286.8	273.5
Professional services	56.5	41.7	104.8	77.6
Total revenue	348.1	309.4	656.1	595.6
Direct and allocated indirect segment operating expenses	259.1	233.2	507.7	453.8
Segment operating income	89.0	76.2	148.4	141.8
Mainframe Service Management [Member]
Revenue:
License	83.7	76.8	154.7	134.8
Maintenance	124.9	116.1	248.3	232.8
Total revenue	208.6	192.9	403.0	367.6
Direct and allocated indirect segment operating expenses	81.2	77.7	164.5	161.2
Segment operating income	$ 127.4	$ 115.2	$ 238.5	$ 206.4

Segment operating income.

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Direct segment operating expenses includes expenses that are directly allocated to particular segments and are controllable by segment management.

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The sum of total indirect expenses that primarily includes operating expenses not specifically identified to a particular segment or controllable by segment management.

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This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

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Revenue earned during the period relating to consideration received from another party for the right to use, but not own, certain of the entity's intangible assets. Licensing arrangements include, but are not limited to, rights to use a patent, copyright, technology, manufacturing process, software or trademark. Licensing fees are generally, but not always, fixed as to amount and not dependent upon the revenue generated by the licensing party. An entity may receive licensing fees for licenses that also generate royalty payments to the entity.

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-Publisher FASB

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Revenue derived from maintenance services provided under contracts or arrangements with clients. For example, it may include the maintenance of software, plant and equipment, and facilities.

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The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

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Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains.

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- Definition

Revenue from providing technology services. The services may include training, installation, engineering or consulting. Consulting services often include implementation support, software design or development, or the customization or modification of the licensed software.

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