Stock-based Compensation (Tables)

3 Months Ended

Dec. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation Expenses

The Company’s stock-based compensation expenses were allocated to the following expense categories:

	Three Months Ended
	December 31,
(Dollars in thousands)	2019		2018
Product costs	$	33	$	32
Research and development		262		213
Selling, general and administrative		1,098		986
Total	$	1,393	$	1,231

Assumptions Used in Stock Option Plans

	Three Months Ended
	December 31,
	2019			2018
Risk-free interest rates		1.6	%		2.9	%
Expected life (years)		4.6			4.5
Expected volatility		37.8	%		33.2	%
Dividend yield		0.0	%		0.0	%