Summary of Significant Accounting Policies (Net Income Per Common Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2018		Sep. 30, 2018	[2]	Jun. 30, 2018	[2]	Mar. 31, 2018	[2]	Dec. 31, 2017	[2]	Sep. 30, 2019	Sep. 30, 2018		Sep. 30, 2017
Accounting Policies [Abstract]
Net income	$ 2,286	[1]	$ 1,648	[1]	$ 1,342	[1]	$ 4,682	[1]	$ 3,340	[1]	$ 2,904	[1]	$ (126)	[1]	$ (4,487)	[1]	$ 9,958	$ 1,631	[2]	$ 9,403	[2]
Denominator for basic net income per common share — weighted average shares outstanding																	27,905,000	27,083,000	[2]	26,432,000	[2]
Effect of dilutive securities:
Stock options and restricted stock units																	649,000	569,000	[2]	667,000	[2]
Denominator for diluted net income per common share — adjusted weighted average shares																	28,554,000	27,652,000	[2]	27,099,000	[2]
Net income per common share:
Basic	$ 0.08		$ 0.06		$ 0.05		$ 0.17		$ 0.12		$ 0.11		$ 0.00		$ (0.17)		$ 0.36	$ 0.06	[2]	$ 0.36	[2]
Diluted net income per common share:
Diluted	$ 0.08		$ 0.06		$ 0.05		$ 0.17		$ 0.12		$ 0.10		$ 0.00		$ (0.17)		$ 0.35	$ 0.06	[2]	$ 0.35	[2]
Antidilutive securities excluded from computation of earnings per share																	744,513	925,063		1,142,322

[1] During fiscal 2019, we recorded a discrete tax benefit of $0.1 million in the first quarter of fiscal 2019 resulting from reversal of income tax reserves due to the expiration of the statutes of limitation as well as excess tax benefits recognized on stock compensation. In the second quarter of fiscal 2019 we recorded a discrete tax benefit of $0.2 million related to the recording of federal and state net operating losses as well as the reversal of income tax reserves due to the expiration of the statutes of limitation. In the third quarter of fiscal 2019, we recorded a discrete tax benefit of $0.3 million from reversal of income tax reserves due to the expiration of the statutes of limitation as well as adjustments from the filing of the federal and foreign income tax returns.During fiscal 2018, we recorded discrete tax expense of $2.8 million in the first quarter of fiscal 2018, $0.2 million in the second quarter of fiscal 2018 and $0.1 million in the third quarter of fiscal 2018 resulting from new U.S. tax legislation that was enacted during the first quarter of fiscal 2018 and the adoption of ASU 2016-09 relating to the accounting for the tax effects of stock compensation. In the fourth quarter of fiscal 2018, we recorded a net tax benefit of $1.5 million for the release of a valuation allowance against U.S. federal capital loss carryforward due to expected capital gains tax in fiscal 2019 resulting from the sale of our corporate headquarters building in October 2018 (see Note 5 to the consolidated financial statements).

[2] Prior period information has been restated for the adoption of ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)”, which we adopted on October 1, 2018.