Stock-Based Compensation - Stock Option Plans (Details) - Employee and Directors Stock Options - USD ($) $ / shares in Units, $ in Thousands						3 Months Ended		6 Months Ended
	Feb. 25, 2019	Nov. 21, 2018	Sep. 17, 2018	Jun. 01, 2018	Nov. 21, 2017	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Mar. 01, 2016
Information relating to stock options
Number of shares authorized						1,925,000		1,925,000
Expiration period								10 years
Vesting of awards per year (as a percent)								33.33%
Award vesting period								3 years
Fair value assumptions
Fair Value (in dollars per share)	$ 10.86	$ 10.61	$ 11.03	$ 13.92	$ 9.74
Dividend Yield (as a percent)	2.52%	2.59%	2.55%	2.07%	2.77%
Risk-Free Interest Rate (as a percent)	2.47%	2.88%	2.89%	2.68%	2.06%
Expected Volatility (as a percent)	41.00%	41.00%	40.00%	41.00%	42.00%
Expected Life	5 years	5 years	5 years	5 years	5 years
Stock-based employee compensation expense						$ 178	$ 144	$ 331	$ 262
Remaining unrecognized compensation expense						$ 1,069		$ 1,069
Weighted average period for recognition								1 year 4 days
Activity under stock option plans, number of shares
Outstanding at beginning of the period (in shares)								410,675
Granted (in shares)								77,760
Exercised (in shares)								(12,084)
Canceled (in shares)								(117,500)
Outstanding at end of the period (in shares)						358,851		358,851
Vested or expected to vest (in shares)						329,060		329,060
Exercisable at end of period (in shares)						232,223		232,223
Outstanding at end of period, Aggregate Intrinsic Value						$ 38		$ 38
Vested or expected to vest, Aggregate Intrinsic Value						36		36
Exercisable at end of the period, Aggregate Intrinsic Value						$ 16		$ 16
Weighted Average Exercise Prices
Outstanding at beginning of the period (in dollars per share)								$ 42.72
Granted (in dollars per share)								34.02
Exercised (in dollars per share)								17.82
Canceled (in dollars per share)								45.70
Outstanding at end of period (in dollars per share)						$ 40.69		40.69
Vested or expected to vest (in dollars per share)						40.55		40.55
Exercisable at end of the period (in dollars per share)						$ 43.70		$ 43.70
Outstanding at end of the period, Weighted Average Remaining Contractual Life								6 years 8 months 19 days
Vested or expected to vest, Weighted Average Remaining Contractual Life								6 years 9 months 7 days
Exercisable at end of the period, Weighted Average Remaining Contractual Life								5 years 3 months 26 days
Stock Option Plan Adopted in January 2007
Information relating to stock options
Number of shares authorized										500,000
Stock Option Plan Adopted In March 2016
Information relating to stock options
Number of shares authorized											425,000