Other Balance Sheet Information Product Warranty and Retrofit Activity on Gross Basis (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Beginning Balance	$ 6,255us-gaap_ProductWarrantyAccrual	$ 6,762us-gaap_ProductWarrantyAccrual	$ 6,499us-gaap_ProductWarrantyAccrual	$ 7,260us-gaap_ProductWarrantyAccrual
Adjustments for Acquisitions and Divestitures	0	0	81	0
Accruals	2,428	2,275	5,145	4,150
Costs Incurred	(2,480)us-gaap_ProductWarrantyAccrualPayments	(2,718)us-gaap_ProductWarrantyAccrualPayments	(5,522)us-gaap_ProductWarrantyAccrualPayments	(5,091)us-gaap_ProductWarrantyAccrualPayments
Ending Balance	$ 6,203us-gaap_ProductWarrantyAccrual	$ 6,319us-gaap_ProductWarrantyAccrual	$ 6,203us-gaap_ProductWarrantyAccrual	$ 6,319us-gaap_ProductWarrantyAccrual

Adjustments to previous product warranty accrual estimates

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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 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.15(5))

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 15

-Subparagraph 5

-Article 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 8

-Subparagraph ((c)(5))

-URI http://asc.fasb.org/extlink&oid=6398077&loc=d3e12565-110249

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- Definition

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

+ 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)(2))

-URI http://asc.fasb.org/extlink&oid=6398077&loc=d3e12565-110249

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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

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)(3))

-URI http://asc.fasb.org/extlink&oid=6398077&loc=d3e12565-110249

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