Commitments and Contingencies - Guarantees and Warranties (Details) $ in Thousands	6 Months Ended
Oct. 31, 2015 USD ($)
Movement in Standard Product Warranty Accrual
Beginning accrued warranty costs	$ 26,481
Warranties issued during the period	7,009
Settlements made during the period	(9,540)
Changes in accrued warranty costs for pre-existing warranties during the period, including expirations	4,514
Ending accrued warranty costs	$ 28,464
Minimum
Warranties:
Standard parts warranty period	1 year
Installation warranty period	1 year
Maximum
Warranties:
Standard parts warranty period	5 years
Installation warranty period	10 years
Performance guarantees \| Letter of credit and bank guarantees agreements
Guarantees:
Performance guarantees outstanding	$ 13,035
Performance guarantees \| Surety bonds
Guarantees:
Performance guarantees outstanding	68,615
Out-of-Home Product Application [Member]
Movement in Standard Product Warranty Accrual
Changes in accrued warranty costs for pre-existing warranties during the period, including expirations	$ 3,180

Product Warranty Accrual, Installation Warranty Coverage Term

No definition available.

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- Definition

Product Warranty Accrual, Standard Parts Warranty Coverage Term

+ References

No definition available.

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- References

No definition available.

+ Details

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- Definition

Amount of loss contingency liability.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- References

No definition available.

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable for estimated claims under standard and extended warranty protection rights granted to customers.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 8

-Subparagraph ((c)(5))

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

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-Subparagraph (SX 210.9-03.15(5))

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 15

-Subparagraph 5

-Article 9

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- Definition

Represents the aggregate decrease in the liability related to payments to satisfy claims for standard and extended product warranties.

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- Definition

Represents the aggregate Increase or Decrease in the liability during the reporting period for accruals related to preexisting standard and extended product warranties (including adjustments for changes in estimates).

+ References

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- Definition

Represents the aggregate increase in the liability for accruals related to standard and extended product warranties issued during the reporting period.

+ References

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