Stock-Based Compensation (Options and Common Shares Reserved for Grant) (Details) - Stock Options $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2020 USD ($) $ / shares shares
Options Outstanding [Roll Forward]
Options Outstanding, Beginning Balance | shares	3,348
Options Outstanding, Granted | shares	796
Options Outstanding, Exercised | shares	(583)
Options Outstanding, Forfeited / Cancelled | shares	(168)
Options Outstanding, Ending Balance | shares	3,393
Options Outstanding, Exercisable | shares	2,115
Weighted Average Exercise Price [Roll Forward]
Weighted Average Exercise Price, Beginning Balance	$ 10.85
Weighted Average Exercise Price, Granted	16.56
Weighted Average Exercise Price, Exercised	10.12
Weighted Average Exercise Price, Forfeited / Cancelled	13.16
Weighted Average Exercise Price, Ending Balance	12.20
Weighted Average Exercise Price, Exercisable	$ 10.80
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Term, Outstanding	3 years 10 months 24 days
Weighted Average Remaining Contractual Term, Exercisable	2 years 10 months 24 days
Aggregate Intrinsic Value, Outstanding | $	$ 12,790
Aggregate Intrinsic Value, Exercisable | $	$ 10,207
Closing Stock Price	$ 15.63