Stockholders' Equity (Stock Options Vested, Or Expected to Vest and Are Exercisable) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015
Stock-Based Compensation
Options outstanding, Number of options	5,074	5,429	4,641
Options outstanding, Weighted-Average Exercise Price	$ 35.13	$ 34.22	$ 32.28
Options outstanding, Weighted-Average Remaining Life in Years	6 years 3 months 18 days
Options outstanding, Aggregate Intrinsic Value	$ 114,200
Options vested and exercisable, Number of options	2,994
Options vested and exercisable, Weighted-Average Exercise Price Per Share	$ 30.68
Options vested and exercisable, Weighted-Average Remaining Life in Years	4 years 8 months 12 days
Options vested and exercisable, Aggregate Intrinsic Value	$ 80,712
Options vested and expected to vest, Number of options	4,964
Options vested and expected to vest, Weighted-Average Exercise Price Per Share	$ 34.99
Options vested and to expected vest, Weighted-Average Remaining Life in Years	6 years 2 months 12 days
Options vested and expected to vest, Aggregate Intrinsic Value	$ 112,451