Stock-Based Compensation Plans (Tables)

12 Months Ended

Sep. 30, 2017

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation Expenses

The Company’s stock-based compensation expenses for the years ended September 30 were allocated to the following expense categories

	2017		2016		2015
Product costs	$	90	$	22	$	24
Research and development		510		324		226
Selling, general and administrative		2,872		3,498		2,131
Total stock-based compensation expense	$	3,472	$	3,844	$	2,381

Assumptions Used in Stock Option Plans

The assumptions used as inputs in the model for the years ended September 30 were as follows:

	2017			2016			2015
Risk-free interest rates		1.74	%		1.89	%		1.43	%
Expected life	4.6 years			4.6 years			4.5 years
Expected volatility		34	%		37	%		43	%
Dividend yield		0	%		0	%		0	%

Schedule of Stock Option Activity

The following table summarizes all stock options activity and stock options outstanding and exercisable under the stock option plans during fiscal 2017, 2016 and 2015:

	Number of Shares			Weighted Average Exercise Price
Outstanding at September 30, 2014		1,210,619		$	20.35
Granted		164,401			21.24
Exercised		(166,422	)		14.54
Forfeited and expired		(90,590	)		35.35
Outstanding at September 30, 2015		1,118,008			20.10
Granted		241,582			20.63
Exercised		(437,850	)		15.68
Forfeited and expired		(94,415	)		31.52
Outstanding at September 30, 2016		827,325			21.30
Granted		229,039			24.08
Exercised		(6,819	)		13.89
Forfeited and expired		(47,640	)		30.65
Outstanding at September 30, 2017		1,001,905			21.54
Exercisable at September 30, 2017		547,051		$	20.80

Schedule of Restricted Stock Awards Activity

The following table summarizes all restricted stock awards activity during fiscal 2017, 2016 and 2015:

	Number of Shares			Weighted Average Grant Price
Balance at September 30, 2014		18,624		$	22.45
Granted		18,073			21.84
Vested		(7,606	)		22.28
Forfeited		(1,316	)		22.16
Balance at September 30, 2015		27,775			22.12
Granted		20,108			20.14
Vested		(12,311	)		22.19
Forfeited		(2,439	)		21.17
Balance at September 30, 2016		33,133			20.96
Granted		51,559			25.12
Vested		(14,497	)		21.10
Forfeited		(2,278	)		25.12
Balance at September 30, 2017		67,917		$	23.98

Schedule of Fair Value at the Date of Grant

The aggregate number of shares that could be awarded to key employees if the minimum, target and maximum performance goals are met, based upon the fair value at the date of grant is as follows:

Performance Period	Minimum Shares		Target Shares		Maximum Shares
Fiscal 2015 – 2017		8,440		42,199		84,398
Fiscal 2016 – 2018		13,268		66,338		132,676
Fiscal 2017 – 2019		10,437		52,185		104,370