Product Warranties (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Changes in the warranty liability [Roll Forward]
Balance, beginning of period	$ 10,521	$ 14,408	$ 11,385	$ 14,681
Accruals for warranties issued in current period	1,385	1,849	2,727	3,398
(Reversals) accruals related to pre-existing warranties	1,689	(624)	1,209	(467)
Settlements made	(1,329)	(2,244)	(2,757)	(4,384)
Effect of exchange rate changes	70	(542)	(228)	(381)
Balance, end of period	$ 12,336	$ 12,847	$ 12,336	$ 12,847

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Amount as of the balance sheet date of the aggregate standard product warranty liability. Does not include the balance for the extended product warranty liability.

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Increase or Decrease in standard product warranty liability due to currency translation. Does not include any Increase or Decrease in an extended product warranty liability due to currency translation.

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Represents the aggregate decrease in the liability for payments made (in cash or in kind) to satisfy claims under the terms of the standard product warranty. Does not include any Increase or Decrease in the liability for payments related to extended product warranties.

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Represents the aggregate Increase or Decrease in the liability during the reporting period for accruals related to preexisting standard product warranties (including adjustments related to changes in estimates). Does not include any Increase or Decrease in the liability for accruals related to extended product warranties.

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Represents the aggregate increase in the liability for accruals related to standard product warranties issued during the reporting period. Does not include any increase in the liability for accruals related to extended product warranties.

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