Restructuring and Related Charges, Activity for Restructuring and Reinvestment Program Liability (Details) - USD ($) $ in Thousands	3 Months Ended
Jul. 31, 2018	Jul. 31, 2017
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
(Credits) charges	$ (6,086)	$ 25,729
Restructuring and Reinvestment Program [Member]
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring liability, beginning of period	20,051
(Credits) charges	(6,086)	25,729
Payments	(5,518)
Foreign translation & reclassifications	254
Restructuring liability, end of period	8,701
Restructuring and Reinvestment Program [Member] \| Severance [Member]
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring liability, beginning of period	17,279
(Credits) charges	(5,778)	24,721
Payments	(4,928)
Foreign translation & reclassifications	(278)
Restructuring liability, end of period	6,295
Restructuring and Reinvestment Program [Member] \| Process Reengineering Consulting [Member]
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring liability, beginning of period	0
(Credits) charges	135	1,521
Payments	(41)
Foreign translation & reclassifications	0
Restructuring liability, end of period	94
Restructuring and Reinvestment Program [Member] \| Other Activities [Member]
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring liability, beginning of period	2,772
(Credits) charges	(443)	$ (513)
Payments	(549)
Foreign translation & reclassifications	532
Restructuring liability, end of period	2,312
Restructuring and Reinvestment Program [Member] \| Other Activities [Member] \| Other Accrued Liabilities [Member]
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring liability, end of period	1,000
Restructuring and Reinvestment Program [Member] \| Other Activities [Member] \| Other Long-Term Liabilities [Member]
Activity for Restructuring and Reinvestment Program liability [Roll Forward]
Restructuring liability, end of period	$ 1,300

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3367-108585

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
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-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of foreign currency translation gain (loss) which decreases (increases) the restructuring reserve.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

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