Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Net Revenues	$ 253,667	$ 201,014	$ 213,571
Cost of Sales	97,419	82,286	82,538
Gross Profit	156,248	118,728	131,033
Operating Expenses:
Research and development	23,729	17,760	16,613
Selling and marketing	26,486	27,995	34,026
General and administrative	44,345	34,044	35,759
Acquisition-related costs	3,890	1,808
Change in fair value of contingent consideration obligation	(6,293)
Restructuring costs	687	2,839	8,706
Selected legal costs	2,080	1,583	4,345
Total operating expenses	94,924	86,029	99,449
Operating Income	61,324	32,699	31,584
Other Income (Expense):
Interest income	142	681	418
Interest expense	(2,632)	(1,945)	(1,520)
Other, net	459	122	(102)
Total other expense	(2,031)	(1,142)	(1,204)
Earnings Before Income Taxes	59,293	31,557	30,380
Income Tax Provision	13,107	7,175	6,531
Net Earnings	$ 46,186	$ 24,382	$ 23,849
Earnings Per Share Data:
Basic earnings per common share	$ 1.08	$ 0.57	$ 0.56
Diluted earnings per common share	$ 1.07	$ 0.57	$ 0.56
Common shares used for basic earnings per common share	42,855	42,571	42,325
Effect of dilutive stock options and restricted share units	319	328	429
Common shares used for diluted earnings per common share	43,174	42,899	42,754
Dividends declared per common share		$ 0.250	$ 0.500
Anti-dilutive Securities:
Common share options and restricted share units	893	1,129	1,007