Stockholders' Equity - Narrative (Details) - USD ($)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2018
Equity [Abstract]
Preferred stock outstanding (in shares)	0
Common stock authorized (in shares)	63,000,000
Common stock issued (in shares)	31,012,326	30,933,110
Common stock outstanding (in shares)	31,012,326	30,933,110
Authorized amount repurchase of common stock			$ 50,000,000.0
Share repurchases (in shares)	362,000
Aggregate repurchased value	$ (3,327,000)	$ (34,624,000)
Average price per share (in dollars per share)	$ 9.20
Remaining availability repurchase amount	$ 12,000,000.0
382 ownership limitation	4.95%