Stock-based Compensation (Tables)

6 Months Ended

Mar. 31, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation Expenses

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

	Three Months Ended				Six Months Ended
	March 31,				March 31,
(Dollars in thousands)	2020		2019		2020		2019
Product costs	$	15	$	32	$	48	$	64
Research and development		168		178		430		391
Selling, general and administrative		1,121		749		2,219		1,735
Total	$	1,304	$	959	$	2,697	$	2,190

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

	Three Months Ended						Six Months Ended
	March 31,						March 31,
	2020			2019			2020			2019
Stock option fair value assumptions:
Risk-free interest rates		1.4	%		2.5	%		1.6	%		2.8	%
Expected life (years)		4.7			4.5			4.6			4.5
Expected volatility		38.4	%		34.9	%		37.9	%		33.4	%
Dividend yield		—	%		—	%		—	%		—	%
Weighted average grant date fair value of stock     options granted	$	13.65		$	18.12		$	14.24		$	18.28