Goodwill and other Identifiable Intangible Assets Goodwill (Details) (USD $)	9 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Sep. 30, 2012
Goodwill [Roll Forward]
Beginning balance	$ 86,209,000	$ 86,012,000
Acquisition of Etherios, Inc.	17,120,000	0
Foreign currency translation adjustment	(718,000)	(468,000)
Ending balance	102,611,000	85,544,000
Goodwill [Line Items]
Market Capitalization	241,400,000
Stockholders' Equity Attributable to Parent	$ 272,262,000		$ 270,857,000
Control Premium		40.00%
Percentage of Fair Value in Excess of Carrying Amount	24.00%
Minimum [Member]
Goodwill [Line Items]
Control Premium		30.00%
Maximum [Member]
Goodwill [Line Items]
Control Premium		45.00%

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- Definition

Percentage above fair value that an investor seeking to acquire control of an entity will pay, used as an input to measure fair value.

+ References

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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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- Definition

Amount of increase (decrease) from foreign currency translation adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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- Definition

Percentage of fair value of reporting unit in excess of carrying amount.

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- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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