Income Taxes (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2017	Nov. 30, 2016
Income Taxes [Line Items]
Effective tax rate	12.60%	11.40%	18.40%	17.80%
Federal statutory rate	35.00%	35.00%	35.00%	35.00%
Net discrete tax benefits	$ 15.5	$ 11.9	$ 28.5	$ 21.1
Significant change in unrecognized tax benefits, nature of event			as a result of statutes of limitations expirations in various tax jurisdictions
Maximum
Income Taxes [Line Items]
Decrease in unrecognized tax benefits	$ 2.0		$ 2.0

Income Taxes [Line Items]

No definition available.

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- Definition

Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (d)(3)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319

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- Definition

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 13
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- Definition

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
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- Definition

Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.

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- Definition

This element provides a description of the nature of the event that could occur within twelve months of the reporting date that would cause a significant increase or decrease in the related unrecognized tax benefit.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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