Quarterly Financial Data (Unaudited) (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	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 54,183	$ 38,700	$ 33,756	$ 33,752	$ 32,489	$ 36,131	$ 34,401	$ 30,215	$ 160,391	$ 133,236
Income from operations	3,394	1,690	2,327	2,557	2,819	2,614	2,204	1,146	9,968	8,782
Interest expense, net	(1,190)	(562)	(545)	(177)	(315)	(262)	(261)	(278)	(2,473)	(1,116)
Income before income taxes	2,204	1,128	1,782	2,380	2,504	2,352	1,943	868	7,495	7,666
Income tax expense	639	325	517	690	747	738	627	3,719	2,171	5,830
Net income	$ 1,565	$ 803	$ 1,265	$ 1,690	$ 1,757	$ 1,614	$ 1,316	$ (2,851)	$ 5,324	$ 1,836
Basic (in dollars per share)	$ 0.13	$ 0.07	$ 0.11	$ 0.14	$ 0.15	$ 0.14	$ 0.11	$ (0.24)	$ 0.44	$ 0.15
Diluted (in dollars per share)	$ 0.12	$ 0.06	$ 0.10	$ 0.13	$ 0.14	$ 0.13	$ 0.10	$ (0.24)	$ 0.41	$ 0.14
Write-down of deferred tax assets from revaluation of net operating losses due to change in federal tax rate								$ 3,400		$ 3,400