Stockholders' Equity (Stock Options Vested, Or Expected to Vest and Are Exercisable) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Stock-Based Compensation
Options outstanding, Number of options	4,944	4,641
Options outstanding, Weighted-Average Exercise Price	$ 35.35	$ 32.28
Options outstanding, Weighted-Average Remaining Life in Years	6 years 1 month 6 days
Options outstanding, Aggregate Intrinsic Value	$ 134,129
Options vested and exercisable, Number of options	2,869
Options vested and exercisable, Weighted-Average Exercise Price Per Share	$ 30.87
Options vested and exercisable, Weighted-Average Remaining Life in Years	4 years 7 months 6 days
Options vested and exercisable, Aggregate Intrinsic Value	$ 90,702
Options vested and expected to vest, Number of options	4,856
Options vested and expected to vest, Weighted-Average Exercise Price Per Share	$ 35.23
Options vested and to expected vest, Weighted-Average Remaining Life in Years	6 years
Options vested and expected to vest, Aggregate Intrinsic Value	$ 132,321