Stock-based Compensation Plans (Tables)

12 Months Ended

Sep. 30, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-based Compensation Expenses

Stock-based compensation expense was reported as follows in the consolidated statements of operations:

	Fiscal Year
(In thousands)	2020		2019		2018
Product costs	$	119	$	135	$	69
Research and development		896		876		801
Selling, general and administrative		4,438		4,066		3,937
Total stock-based compensation expense	$	5,453	$	5,077	$	4,807

Stock Option Fair Value Assumptions and Weighted Average Fair Value of Stock Options Granted

Stock option fair value assumptions and the weighted average fair value of stock options granted were as follows:

	Fiscal Year
	2020			2019			2018
Stock option fair value assumptions:
Risk-free interest rates		1.41	%		2.75	%		2.18	%
Expected life (years)	4.6			4.5			4.8
Expected volatility		39	%		34	%		33	%
Dividend yield		—	%		—	%		—	%
Weighted average grant date fair value of stock     options granted	$	14.13		$	17.89		$	10.91

Schedule of Stock Option Activity

Stock option activity was as follows:

(In thousands, except per share data)	Number of Shares			Weighted Average Exercise Price
Options outstanding at September 30, 2017		1,002		$	21.54
Granted		270			34.08
Exercised		(450	)		19.46
Forfeited and expired		(111	)		30.18
Options outstanding at September 30, 2018		711			26.28
Granted		179			55.09
Exercised		(13	)		22.03
Forfeited and expired		(6	)		42.28
Options outstanding at September 30, 2019		871			32.18
Granted		299			41.06
Exercised		(125	)		22.89
Forfeited and expired		(105	)		41.69
Options outstanding at September 30, 2020		940			35.18
Options vested and exercisable at September 30, 2020		472		$	28.65

Schedule of Restricted Stock Activity

Restricted Stock activity was as follows:

(In thousands, except per share data)	Number of Shares			Weighted Average Grant Price
Unvested restricted stock awards at September 30, 2017		68		$	23.98
Granted		56			34.38
Vested		(29	)		23.78
Forfeited		(10	)		29.10
Unvested restricted stock awards at September 30, 2018		85			30.30
Granted		45			56.05
Vested		(39	)		28.61
Forfeited		(1	)		47.86
Unvested restricted stock awards at September 30, 2019		90			43.69
Granted		67			41.40
Vested		(43	)		38.74
Forfeited		(14	)		44.76
Unvested restricted stock awards at September 30, 2020		100		$	44.16