Disposition of Business (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Nov. 07, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Document Period End Date			Sep. 30, 2019
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net				$ 30,959
Disposal Group, Including Discontinued Operation, Consideration						$ 400,000
Gain (Loss) on Disposition of Business	$ 102,400		$ 102,371	0	$ 0
Disposal Group, Including Discontinued Operation, Revenue		$ 2,400	67,430	209,363	211,187
Disposal Group, Including Discontinued Operation, Operating Expense		1,400
Provision for Income Taxes, Discontinued Operations		$ 1,600	(2,688)	5,513	8,310
Disposal Group, Including Discontinued Operation, Costs of Goods Sold			16,946	48,183	49,962
Other			(538)	(1,821)	(21,210)
Disposal Group, Including Discontinued Operation, Operating Income (Loss)			(5,587)	30,489	35,655
Net income from discontinued operations			99,472	24,976	27,345
Depreciation, Discontinued Operations			391	1,995	2,397
Disposal Group, Including Discontinued Operation, Depreciation and Amortization			6,569	23,083	28,017
Stock Compensation Expense, Discontinued Operations			7,103	7,876	11,371
Disposal Group, Including Discontinued Operation, Prepaid and Other Assets				3,443
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment				2,442
Disposal Group, Including Discontinued Operation, Goodwill				257,352
Disposal Group, Including Discontinued Operation, Intangible Assets				99,507
Disposal Group, Including Discontinued Operation, Other Assets				196
Disposal Group, Including Discontinued Operation, Assets				393,899
Disposal Group, Including Discontinued Operation, Accounts Payable				3,604
Disposal Group, Including Discontinued Operation, Accrued Liabilities				12,304
Disposal Group, Including Discontinued Operation, Deferred Revenue				107,965
Disposal Group, Including Discontinued Operation, Other Liabilities				2,658
Disposal Group, Including Discontinued Operation, Liabilities				126,531
Other Expense [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Operating Expense			5,219	17,096	21,056
Acquisition-related Costs [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Operating Expense			(386)	8	32
General and administrative
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Operating Expense			1,997	3,890	3,612
Selling and Marketing Expense
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Operating Expense			28,433	76,593	73,760
Research and development
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Operating Expense			7,557	26,588	26,172
Restructuring Charges [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Operating Expense			13,251	6,472	1,131
Other			$ 0	$ 44	$ (193)