Stock-Based Compensation - Performance Shares (Details) - Performance shares (PSUs)	12 Months Ended
	Sep. 30, 2021 $ / shares shares
Weighted Average Price
Nonvested shares, weighted average grant date fair value at beginning period (in dollars per share) | $ / shares	$ 26.07
Granted (in dollars per share) | $ / shares	27.84
Vested (in dollars per share) | $ / shares	84.97
Forfeited (in dollars per share) | $ / shares	69.91
Nonvested shares, weighted average grant date fair value at ending period (in dollars per share) | $ / shares	$ 24.40
Performance Shares/Units
Nonvested shares at beginning period (in shares) | shares	903,401
Granted (in shares) | shares	379,629
Vested (in shares) | shares	(5,958)
Forfeited (in shares) | shares	(53,892)
Nonvested shares at ending period (in shares) | shares	1,223,180