Stock-Based Compensation - Stock Option Plans (Details) - Employee and Directors Stock Options - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	Nov. 19, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Fair value assumptions
Fair Value (in dollars per share)	$ 9.66
Dividend Yield (as a percent)	2.38%
Risk-Free Interest Rate (as a percent)	1.65%
Expected Volatility (as a percent)	35.00%
Expected Life	5 years
Stock-based employee compensation expense		$ 261	$ 198	$ 779	$ 529
Remaining unrecognized compensation expense		$ 1,840		$ 1,840
Weighted average period for recognition				1 year 8 months 26 days
Activity under stock option plans, number of shares
Outstanding at beginning of the period (in shares)				482,391
Granted (in shares)				91,466
Exercised (in shares)				(12,400)
Outstanding at end of the period (in shares)		561,457		561,457
Vested or expected to vest (in shares)		509,918		509,918
Exercisable at end of period (in shares)		299,093		299,093
Weighted Average Exercise Prices
Outstanding at beginning of the period (in dollars per share)				$ 38.05
Granted (in dollars per share)				37.00
Exercised (in dollars per share)				34.00
Outstanding at end of period (in dollars per share)		$ 37.97		37.97
Vested or expected to vest (in dollars per share)		37.92		37.92
Exercisable at end of the period (in dollars per share)		$ 40.67		$ 40.67
Outstanding at end of the period, Weighted Average Remaining Contractual Life				7 years 6 months 25 days
Vested or expected to vest, Weighted Average Remaining Contractual Life				7 years 4 months 9 days
Exercisable at end of the period, Weighted Average Remaining Contractual Life				5 years 11 months 1 day