Stock-Based Compensation (Schedule of Restricted Stock Units Activity) (Details) - Restricted Stock Units (RSUs) - $ / shares	12 Months Ended
	Sep. 30, 2016		Sep. 30, 2015	Sep. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding Beginning Balance, Number of Restricted Stock Units	133,506		106,845	81,555
Granted, Number of Restricted Stock Units	168,800		89,500	57,200
Vested, Number of Restricted Stock Units	(116,568)	[1]	(55,431)	(29,832)
Forfeited, Number of Restricted Stock Units	(25,750)		(7,408)	(2,078)
Outstanding Ending Balance, Number of Restricted Stock Units	159,988		133,506	106,845
Outstanding Beginning Balance, Weighted Average Fair Value Per Share	$ 47.83		$ 51.30	$ 38.66
Granted, Weighted Average Fair Value Per Share	31.64		41.75	66.15
Vested, Weighted Average Fair Value Per Share	33.10	[1]	45.23	44.88
Forfeited, Weighted Average Fair Value Per Share	50.28		43.82	56.34
Outstanding Ending Balance, Weighted Average Fair Value Per Share	$ 43.12		$ 47.83	$ 51.30

[1] Includes the accelerated vesting of 84,043 shares previously issued to our former Chief Executive Officer and other senior managers as part of their separation packages, see Note M.