Disposition of Business (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2019	Feb. 01, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash Provided by (Used in) Operating Activities, Discontinued Operations			$ (13,307)	$ 51,418
Document Fiscal Year Focus			2020	2019
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net					$ 67,928
Provision for Income Taxes, Discontinued Operations		$ (4,730)		$ (4,069)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	$ 0	105,729	$ (6,192)	110,938
Depreciation, Discontinued Operations		2,162		4,592
Disposal Group, Including Discontinued Operation, Depreciation and Amortization		7,142		17,602
Stock Compensation Expense, Discontinued Operations		10,074		17,019
Disposal Group, Including Discontinued Operation, Prepaid and Other Assets					23,930
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment					20,113
Disposal Group, Including Discontinued Operation, Goodwill					1,115,568
Disposal Group, Including Discontinued Operation, Intangible Assets					65,561
Disposal Group, Including Discontinued Operation, Other Assets					35,366
Disposal Group, Including Discontinued Operation, Assets					1,328,466
Disposal Group, Including Discontinued Operation, Accounts Payable					14,039
Disposal Group, Including Discontinued Operation, Accrued Liabilities					27,429
Disposal Group, Including Discontinued Operation, Deferred Revenue					353,700
Disposal Group, Including Discontinued Operation, Revenue		88,434		214,408
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income			11,674
Disposal Group, Including Discontinued Operation, Consideration						$ 404,000
Disposal Group, Including Discontinued Operation, Costs of Goods Sold		27,274		68,596
Disposal Group, Including Discontinued Operation, Operating Income (Loss)		(1,372)		4,498
Disposal Group, Including Discontinued Operation, Other Liabilities					21,603
Disposal Group, Including Discontinued Operation, Liabilities					$ 416,771
Gain (Loss) on Disposition of Business		102,371		102,371
Disposal Group, Capital Expenditures		(1,091)		(1,871)
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		16,402		33,302
Other Operating Income		(266)		(250)
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		182		31
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		4,437		11,483
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		1,331		3,145
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		18,315		44,494
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		22,131		49,109
Imaging [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Provision for Income Taxes, Discontinued Operations		(4,363)		(2,688)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent		98,081		99,472
Depreciation, Discontinued Operations		97		391
Disposal Group, Including Discontinued Operation, Depreciation and Amortization		1,643		6,569
Stock Compensation Expense, Discontinued Operations		5,001		7,103
Disposal Group, Including Discontinued Operation, Revenue		15,435		67,430
Disposal Group, Including Discontinued Operation, Costs of Goods Sold		4,942		16,946
Disposal Group, Including Discontinued Operation, Operating Income (Loss)		(8,653)		(5,587)
Gain (Loss) on Disposition of Business		102,371		102,371
Disposal Group, Capital Expenditures		0		0
Imaging [Member] | 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		4,791		13,251
Other Operating Income		0		0
Imaging [Member] | 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		0		(386)
Imaging [Member] | 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		1,305		5,219
Imaging [Member] | 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		766		1,997
Imaging [Member] | 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		10,243		28,433
Imaging [Member] | 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		2,041		7,557
Automotive Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Provision for Income Taxes, Discontinued Operations	0	(367)	1,194	(1,381)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	0	7,648	(6,192)	11,466
Depreciation, Discontinued Operations	0	2,065	0	4,201
Disposal Group, Including Discontinued Operation, Depreciation and Amortization	0	5,499	0	11,033
Stock Compensation Expense, Discontinued Operations	0	5,073	0	9,916
Disposal Group, Including Discontinued Operation, Revenue	0	72,999	0	146,978
Disposal Group, Including Discontinued Operation, Costs of Goods Sold	0	22,332	0	51,650
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	0	7,281	(7,386)	10,085
Gain (Loss) on Disposition of Business	0	0	0	0
Disposal Group, Capital Expenditures	0	(1,091)	0	(1,871)
Automotive Segment [Member] | 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	0	11,611	7,386	20,051
Other Operating Income	0	(266)	0	(250)
Automotive Segment [Member] | 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	0	182	0	417
Automotive Segment [Member] | 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	0	3,132	0	6,264
Automotive Segment [Member] | 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	0	565	0	1,148
Automotive Segment [Member] | 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	0	8,072	0	16,061
Automotive Segment [Member] | 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	$ 0	$ 20,090	$ 0	$ 41,552