Goodwill and other Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 121,093	$ 122,910
Accumulated amortization	(90,426)	(83,590)
Net	30,667	39,320	[1]
Purchased and Core Technology
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	57,699	58,102
Accumulated amortization	(50,986)	(48,693)
Net	6,713	9,409
License Agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	102	102
Accumulated amortization	(74)	(46)
Net	28	56
Patents and Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	14,577	15,701
Accumulated amortization	(11,970)	(12,242)
Net	2,607	3,459
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	46,315	46,605
Accumulated amortization	(25,266)	(21,049)
Net	21,049	25,556
Non-compete Agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	600	600
Accumulated amortization	(330)	(210)
Net	270	390
Order backlog
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,800	1,800
Accumulated amortization	(1,800)	(1,350)
Net	$ 0	$ 450

[1] Prior period information has been restated for the adoption of ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)”, which we adopted on October 1, 2018.