Accumulated Other Comprehensive Loss - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Beginning Balance	$ 178,715	$ 171,397	$ 178,847	$ 176,587
Changes in unrealized gain on available-for-sale securities, net of tax		19		83
Foreign currency translation adjustments	(1,017)	238	(451)	20
Ending Balance	166,427	172,953	166,427	172,953
Accumulated Other Comprehensive Loss
Beginning Balance	(15,191)	(15,773)	(15,757)	(15,619)
Ending Balance	$ (16,208)	$ (15,516)	$ (16,208)	$ (15,516)

Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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Amount after tax, before reclassification adjustments, of unrealized holding gain (loss) on available-for-sale securities.

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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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