Stock-based Compensation - Stock Options Outstanding (Details) - Stock Options	3 Months Ended
	Dec. 31, 2018 $ / shares shares
Shares
Outstanding at beginning of period (shares) | shares	533,052
Granted (shares) | shares	25,230
Exercised (shares) | shares	(1,000)
Forfeited (shares) | shares	(1,319)
Outstanding at end of period (shares) | shares	555,963
Exercisable at end of period (shares) | shares	504,092
Vested or expected to vest in the future (shares) | shares	552,799
Weighted Average Exercise Price
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 14.26
Granted (in dollars per share) | $ / shares	10.38
Exercised (in dollars per share) | $ / shares	7.56
Forfeited (in dollars per share) | $ / shares	11.53
Outstanding at end of period (in dollars per share) | $ / shares	14.10
Exercisable at end of period (in dollars per share) | $ / shares	14.13
Vested or expected to vest in the future (in dollars per share) | $ / shares	$ 14.13