Disposition of Business (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Feb. 01, 2019	Nov. 07, 2018	Sep. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	$ 30,492				$ 30,959
Provision for Income Taxes, Discontinued Operations	1,675	$ 448
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	1,391	5,763
Depreciation, Discontinued Operations	294	417
Disposal Group, Including Discontinued Operation, Depreciation and Amortization	4,926	6,065
Stock Compensation Expense, Discontinued Operations	2,102	1,761
Disposal Group, Including Discontinued Operation, Prepaid and Other Assets	4,979				3,443
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment	2,321				2,442
Disposal Group, Including Discontinued Operation, Goodwill	257,129				257,352
Disposal Group, Including Discontinued Operation, Intangible Assets	94,356				99,507
Disposal Group, Including Discontinued Operation, Other Assets	5,989				196
Disposal Group, Including Discontinued Operation, Assets	395,266				393,899
Disposal Group, Including Discontinued Operation, Accounts Payable	6,611				3,604
Disposal Group, Including Discontinued Operation, Accrued Liabilities	13,795				12,305
Disposal Group, Including Discontinued Operation, Deferred Revenue	93,547				107,965
Disposal Group, Including Discontinued Operation, Revenue	51,995	54,421
Disposal Group, Including Discontinued Operation, Consideration			$ 390,000	$ 400,000
Disposal Group, Including Discontinued Operation, Costs of Goods Sold	12,004	12,956
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	3,066	6,211
Disposal Group, Including Discontinued Operation, Other Liabilities	3,025				2,657
Disposal Group, Including Discontinued Operation, Liabilities	116,978				$ 126,531
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	8,460	1,232
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)	0
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	3,914	4,223
General and Administrative Expense
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Operating Expense	1,231	1,119
Sales and marketing
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Operating Expense	18,190	21,400
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	$ 5,516	$ 7,280