Stockholders' Equity (Changes in Non-vested Stock Options) (Details) - Stock Options [Member] - $ / shares shares in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, beginning balance	1,988
Weighted-Average Grant Date Fair Value Per Share, beginning balance	$ 21.64
Options granted, Number of options	924
Options granted, Weighted-Average Grant Date Fair Value Per Share	$ 24.12	$ 25.66	$ 24.98
Options vested, Number of options	(800)
Options vested, Weighted-Average Grant Date Fair Value Per Share	$ 19.81
Options forfeited, Number of options	(44)
Options forfeited, Weighted-Average Grant Date Fair Value Per Share	$ 22.91
Number of Options, ending balance	2,068	1,988
Weighted-Average Grant Date Fair Value Per Share, ending balance	$ 23.43	$ 21.64