Stockholders' Equity (Activity for Stock Option Awards) (Details) shares in Thousands	12 Months Ended
	Sep. 30, 2017 $ / shares shares
Stock-Based Compensation
Number of options, beginning balance | shares	4,944
Weighted Average Exercise Price Per Share, beginning balance | $ / shares	$ 35.35
Options granted, Number of options | shares	791
Options granted, Weighted Average Exercise Price Per Share | $ / shares	$ 62.74
Options exercised, Number of options | shares	(466)
Options exercised, Weighted Average Exercise Price Per Share | $ / shares	$ 33.65
Options forfeited, Number of options | shares	(33)
Options forfeited, Weighted Average Exercise Price Per Share | $ / shares	$ 44.21
Number of options, ending balance | shares	5,236
Weighted Average Exercise Price Per Share, ending balance | $ / shares	$ 39.58