Discontinued Operations - Financial Results (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Net income (loss)	$ (182)	$ 427,862	$ 48,747
Discontinued Operations, Held-for-sale
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Total revenue		109,518	196,096
Total cost of revenue		66,164	108,184
Gross profit		43,354	87,912
Research and development		6,605	7,605
Selling, general and administrative	(171)	20,889	25,017
Restructuring charges		24	2
Total operating expenses	(171)	27,518	32,624
Operating income	171	15,836	55,288
Other income (loss), net	(410)	539,948	1,091
Income (loss) before income taxes and earnings of equity method investment	(239)	555,784	56,379
Income tax provision (benefit)	(57)	134,110	14,420
Income (loss) before equity in earnings of equity method investment	(182)	421,674	41,959
Equity in earnings of equity method investment		6,188	6,788
Net income (loss)	$ (182)	427,862	48,747
Discontinued Operations, Held-for-sale \| Products
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Total revenue		76,227	150,365
Total cost of revenue		47,148	85,350
Discontinued Operations, Held-for-sale \| Services
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Total revenue		33,291	45,731
Total cost of revenue		$ 19,016	$ 22,834

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Discontinued Operation Income Loss From Discontinued Operation Before Earnings Losses of Equity Method Investments

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Disposal Group Including Discontinued Operation Restructuring Charges

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Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal.

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Amount after tax of income (loss) from a discontinued operation including the portion attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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